Is there a universal NIOSH definition of "inert"?

Discussion in 'Black and White' started by patrick_gainer, Jul 8, 2004.

  1. Recent controversy over what MSDS may mean by "inert" led me to search
    for the NIOSH definition. I found it at:

    http://www.ilpl.com/msds/ref/niosh.html

    If it does not come up at first, you may have to reboot and try again.

    It may or may not be required to specify on the MSDS how much of a
    material is inert, but when it is specified, the official NIOSH
    definition of "inert" is as follows:


    Definition
    An inert chemical substance is one that is not generally reactive.
    This is a synonym for "inactive" with respect to chemical reactions.

    Additional Info
    In the periodic table of the elements (graphic omitted), the inert
    elements are the noble gases, helium (He), neon (Ne), argon (Ar),
    krypton (Kr), xenon (Xe), and radon (Rn). Nitrogen (which occurs as N2
    gas) is also considered inert:


    These elements are unreactive because they are very stable in their
    naturally occurring forms. While some of these can be made to react
    chemically, their compounds are usually not very stable (except for
    nitrogen). The term inert atmosphere is usually used to denote a
    nitrogen or argon atmosphere in a container.

    Chemical compounds can also be considered inert. For example,
    poly(tetrafluoroethylene), better known by the DuPont tradename
    TeflonTM, does not react with most substances. Likewise, sand, SiO2,
    is generally unreactive.

    We can also use the term to describe reactivity towards particular
    substances. For example, mercury reacts with aluminum metal (which is
    one reason why it is illegal to transport liquid mercury by aircraft)
    but is inert towards iron metal. Carbon dioxide is inert to many
    chemical reactions, but reacts violently with alkali metals such as
    sodium and potassium. Using a carbon dioxide fire extinguisher would
    be a VERY bad idea for a sodium metal fire!


    MSDS Relevance
    Inert materials are good choices for chemical containers. For example,
    acid waste should not be stored in metal drums because these will
    quickly corrode. However, glass or polyethylene containers are inert
    to most acids.
    If a chemical spill occurs, one may need to clean up the spill by
    using an inert absorbing material such as vermiculite or sand. The
    MSDS will usually recommend a specific material, but not always. If in
    doubt, phone the manufacturer listed on the MSDS.

    End of NIOSH definition.

    The argument that an inert material in one application may be active
    in another is true for certain materials, but that will be stated in
    the MSDS when it is true. It is certainly not true for most of the
    materials we use in developers and the like. For us, if the term
    "inert" is used without exceptions, it means "chemically inactive" and
    thus cannot include such materials as salt, bromides, and the like.
     
  2. I've never had a bit of trouble with sodium carbonate from the pool store, but it would be very interesting to have a sample analyzed to find out just what the one or two percent "inert" portion consists of. The other worry is quantities of substances so low that nobody in the safety world cares about them, but that might affect film development so far as fogging or somesuch. My last developer blend contained such things as rose hips from the vitamin C and whatever coating is on aspirin, but I just filtered out what wouldn't disolve and, again, no problems. In 35 years of photography I've never lost a roll due to a chemical problem, but I can't say the same for "photographer problems".
     
  3. Patrick;

    We can keep going round and round on this. Teflon is inert. Ok, if you handle teflon powder, then go outside and smoke a cigarette, the powder gets into the paper from you hands, is vaporized (no reaction here AFAIK) and into your lungs where it causes flu like symptoms and other respiratory distress. So what. NIOSH or whoever says it is inert. Not under all conditions.

    Sodium chloride is inert in a house fire. The firemen don't have to worry about your salt in the cupboard. It is defined as inert by NIOSH and MSDS then, I guess. IDK. Kirk Keyes is the expert.

    I am a research chemist with about 40 years of practical experience. Others match or exceed my experience. Probably most exceed my knowledge of chemistry. IDK. I know that I take lab precautions and use chemicals as pure as possible. I take safety very seriously and also repeatability and quality very seriously. I see glaring loopholes in almost every 'comparison' 'formula' or 'test' on this forum or in photo magazines, because they are being done in many cases by rank amateurs. I hasten to add that I have seen some superb work here and in magazines for both design of experiment and data, for example the recent work by James Dainis on another thread.

    Please read Danny's post about fixer solution problems with a 'known' good formula from Anchell's book. Water of hydration ruined his mix, if our tests are right. He did a good job of finding the problem and solution.

    I don't know what your background is, but I have had 7 years of college taught chemistry in addition to the experience mentioned above, and I don't want to give ambiguous or imprecise information to people untrained in chemistry or the scientific method. With my education, I have trouble enough understanding NIOSH and MSDS definitions and I have trouble enough with balky photographic film, paper, and solutions.

    Take Kirks word for it. Impurities can be bad for photography but inert otherwise. Also, consider that volumetric measurement of solids is not a good laboratory practice, and in addition there are photographic parameters beyond H&D curves and picture tests.

    Lets stop beating a dead horse. Or, lets let Kirk's word be the final arbiter for these MSDS and NIOSH things. I respect his judgment and his knowledge.

    I built a bridge out of balsa wood for my model trains, and it works fine. I would not even consider building a bridge for Amtrak. Think about the implications in this parargraph. 'Nuff said.

    Ron Mowrey
     
  4. Ron,

    Correct me if I am wrong, but,

    As to unexpected, but often predictable, consequences... like the noble gasses, "di-hydrogen monoxide" is also "inert" according to OSHA but it will kill you [dead; deceased; kaput!] if you try to breathe it in quantity.

    In pure liquid form at room temperatures it will not conduct electricity - but if only slightly contaminated it generally will.

    It may not be normally flamable but at extremely high temperatures can break down into a flamable component (H2) and a component that, though not itself flamable is very reactive (O[2]}

    Nuff said
    ;-)
     
  5. Dai, Conrad;

    That is exactly my point.

    Put something unknown into a photographic solution and you might lose your photographs. They might look good, but might have a microscopic fault that is not apparent to the naked eye. Indeed, if you didn't have a side by side complete comparison with some sort of reference, you would not know what, if anything, went wrong.

    I have tried and tried to bring to your collective attentions that micro imaging is important. Edge effects make or break a photographic system, not macro effects such as an H&D curve.

    A side by side print comparision of a sharpness chart might resolve your uncertainty about a given process or chemical, but as I said over and over, "If you are happy, that is what counts". I'm just adding on two caveats "You might not know what you are missing" and "Someday something might go wrong".

    I hope you have all read Danny's fixer problem thread by now. It is quite relevant to this entire topic.

    I am only pointing out that it is the uncertainty that is the problem.

    Oh, Conrad, BTW, is your carbonate anh or monohydrate? Do you know? My bottles from Aquachem don't state. They could leave the plant in sealed containers as anh. and now be half way or something in between to becoming the monohydrate. They might contain bicarbonate or lye as contaminants as well as sea salts such as Magnesium Carbonate and Calcium Carbonate, etc. as well as halide salts. Kirk Keyes has made a significant contribution to this topic. We should not ignore his comments about purity, NIOSH and MSDS.

    Ron Mowrey
     
  6. Patrick - I am not convinced that this web page link you give really contains a NIOSH definition of "inert". While it does talk abont MSDSs an NIOSH, this site looks to me to be a collections of safetly definitions that someone has put together. Perhaps you can find something more authoritative from NIOSH directly...

    I know this will get us away from photography and into hazardous waste, transtortation, and other safety issues, but anyway...

    Lets look at the first sentence of your "Definition - An inert chemical substance is one that is not generally reactive. This is a synonym for "inactive" with respect to chemical reactions."

    The first part of the sentence is good, I think they missed the point with the second one thought. The word to pay attention to is "reactive". That is a very important word in the safety field - and it has a legal definition. The following is from a DOT website:

    Reactive wastes are solid wastes that exhibit any of the following properties as defined at 40 CFR 61.23(a):

    ?it is normally unstable and readily undergoes violent changewithout detonating.?

    ?it reacts violently with water.?

    ?it forms potentially explosive mixtures with water.?

    ?when mixed with water, it generates toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment.?

    ?it is a cyanide or sulfide bearing waste which, when exposed to pH conditions between 2 and 12.5, can generate toxic gases, vapors or fumes in a quantity sufficient to present a danger to human health or the environment.?

    ?it is capable of detonation or explosive reaction if it is subjected to a strong initiating source or if heated under confinement.?

    ?it is readily capable of detonation or explosive decomposition or reaction at standard temperature and pressure.?

    ?it is a forbidden explosive as defined in 49 CFR 173.51, or a Class A explosive as defined in 49 CFR 173.53 or a Class Bexplosive as defined in 49 CFR 173.88.?

    (End of info from DOT site.)

    That is the definition of reactive, and it goes hand in hand with materials that are "ingitable", "corrosive", and when placed together "incompatible".

    You say, "The argument that an inert material in one application may be active in another is true for certain materials, but that will be stated in the MSDS when it is true."

    That's somewhat true! Several sections in the MSDS state this info. Section 5 - Fire Fighting Measures, Section 7 - Handling and Storage, Section 10 - Stability and Reactivity (that's that word "reactivity" again) all have this type of info. But you can see by reading them that they are talking about safety. Not chemical analysis. They will not have a listing of what is inert in a photographic application vs. a cosmetic application. They are concerned with things like what happens when the fire fighters add water to this material.

    Once again, I think your idea that a document designed for safety can be used for chemical analyses is off base.
     
  7. Conrad - I used to work at a lab that tested soda ash (bulk sodium carbonate) before it was shipped to China (where it was probably purified to sodium carbonate and sent back to the USA).

    I went to the loading dock at the port once, and the soda ash arrives in traincars, it is dumped out the bottom of the cars onto conveyor belts, carried into a large warehouse (300x100 ft I think), piled up tens of feet and held there until a ship arrives. When the ship got there, the material was put back onto the conveyor belt, and transported on to the ship. Not a good method if you are trying to keep something from getting contaminated with dirt, but, again, this was bulk soda ash (like what is in the pool pH plus chems).

    We did the tests specified to meet the certifications required for soda ash. The tests were simple tests, much the same as described in the other thread. Unfortunately I don't have a copy of the specifications, but I can tell you they were pass/fail tests. Things like moisture content, a turbidometric (nephalometry - see the other thread where I descibed this test) for halogens (choride, bromide..), insoluble matter and other tests in this vein.

    But as you say, your pool chems have been meeting your needs, so why not use them. Ron's concern is that some people have higher needs, and materials like this may not meet those needs without a lot more testing.
     
  8. Ron - Nice piont about teflon, but I can tell you that there is a chemical reaction going on there. The teflon is being oxydized (burned) they the heat of the cigarette, and it is producing hydrofluoric acid. Not something you want in your lungs. In addition to testing soda ash years ago, I also did plastics identifications - one of the tests for identifing teflon and other fluorocarbon plastics is to burn them with a bunsen burner and test the pH of the vapours that are produced. When most things burn, the vapors have a mildly acidic pH (4-5), when fluorinated materials burn, they have a very low pH, about pH 1 or so.

    Since we've all realized that MSDSs are for safety info, let's look at a few lines from Dupont's MSDS for Telfon - "Hazardous decomposition products including carbon dioxide, carbon monoxide, hydrogen fluoride, toxic gases or particles may be formed during combustion. These products may cause severe eye, nose, and throat irritation or toxic effects. [...] Wear self-contained breathing apparatus. Avoid breathing decomposition products."

    And since we're on the subjust of inert materials, try heating up some concentrated sulfuric acid in a teflon beaker - it will make a big mess - but probably because the teflon melts at those temperatures. But incompatable materials nonetheless.

    By the way Ron, thanks for the title of "expert" - but I'm not really. I just have more experience than most others here as I have to use tools like MSDS and chemical analyses on a daily basis.

    It sounds to me like Lex could give some more input as well on this subject as well.
     
  9. Kirk;

    I knew about the HF, but it was my impression from an article that there were effects from inhaled CFs in the lungs that were absorbed into the blood stream. Something that gave the flu like symptoms that could not be explained by HF. HF would have just caused serious lung problems.

    The symptoms described among teflon workers went beyond HF inhalation or absorption.

    Anyhow, this effect was known long ago. Even overheated teflon coated cookware can cause problems.

    Thanks for the contributions and clarifications.

    Ron Mowrey
     
  10. I've spent a fair amount of time pondering edge effects and acutance, since that's the main battle with my PPD formulas. Those effects are really important, but I don't ignore the H&D curve either. The problem is that I use a variety of chemicals, sometimes Kodak, sometimes Photographer's Formulary, and sometimes grocery store and pool chemicals. The number of potential combinations, and possible effects of contaminants, are huge. Unmanagable in fact, and I don't have the time or inclination to do the tests. I like to think I have enough experience to spot problems quickly, and identify the cause, but there are certainly subtle things that could get by me. The reason I don't lose much sleep over any of this is something I've stated in other posts- I don't experiment with images I consider important. I have a few very specific film & developer combinations I use when the results are important to me. Specifically, FP4+ with FX2 (made from PF chems), and Tri-X in HC-110 dilution B. Even though my PPD formula seems to be working well, I don't yet treat it as a bulletproof receipe. I need to know how it ages, how it works with a variety of films, and how it works with "real" chemicals, vs the supermarket stuff I started with. Bottom line is that I'm pretty conservative. Remember though, the more knowledge you have, the more potential problems you can probably identify. That should be balanced by the fact that we have remarkably few reports of anyone actually having a problem due to contaminants. BTW, IDK on the type of hydrate, and I should!
     
  11. All of the concernes over chemical purity are valid in theory, but in my personal practice are simply not a factor. I've made up liters of highly concentrated developers of Patrick's formulation, and have had the most consistent results I've ever had with any developer. These developers are made up with TEA and PG, and are very active, requiring only 10-20ml of concentrate per roll or 8x10 sheet of film, making them very economical in addition to being very stable, and between the two formulae, I can make up any kind of developer I need, including paper developer. I know that you are arguing a specific, theoretical point about what CAN happen when using chemicals of unknown purity, but I thought I'd share what HAS happened. While I don't own a balance, I do have a densitometer, and Kodak Control Strips with which I measure the activity of my developers periodically, and I can see that these developers are a lot more stable than the developers we used at the pro lab where I worked. These developers just don't move, even with my teaspoon measurement of Ph Plus and 20 Mule Team Borax. I know; I'm not a chemist and have no business discussing these issues with men of your collective education, but I believe that it was for people like myself, dedicated amateur photographers, that Patrick developed these formulae, and in my case, the formulae work as intended with absolute predictability. Its very easy and safe to recommend only the purest chemicals available, but I encourage you to find a failure in practce before condemning the methods and chemicals that Patrick suggests.
     
  12. Re: the decomposition of hot Teflon -- I believe that in addition to oxidation, Teflon can be "heat-cracked" to revert to the monomer and related compounds. Tetrafluoroethylene should be a strong electrophile and not very healthy! I'm not sure what the precise "cracking" conditions are.

    And Kirk -- Is pool-grade sodium carbonate really just unrefined soda ash? Obviously the pool stuff ain't analytical grade and there will be impurities, as we've been discussing for a long time, but I've never seen the claim before that it is completely unrefined material.
     
  13. Jay;

    That is good information to have, and the first I have seen here that has some reliable checks and balances, the control strips.

    Thanks for that contribution.

    Do you have any information on image sharpness and granularity to share? I would be very interested in your data.

    BTW, did you see my post in your paste thread? I chimed in too late, but added some information you might be interested in.

    Ron Mowrey
     
  14. Rowland, thank you for the goo information in the paste thread, it is a real priveledge for me to be able to discuss my hairbrained schemes with a man of your education and experience. Regarding the developers I've been using, I'm afraid I don't know how to measure sharpness and granularity quantitatively. I have no resolution test targets, or a microscope. If there is a procedure that I could perform to generate the information you want, I'd be happy to do so, and send you the print/negative for evaluation. I will post scans of 8x10 prints from 6x7 negatives when my scanner comes back to life, but I can't imagine that they will have any quantitative value.
     
  15. Jay,
    Good question - I have been hinting at that, haven't I? I was trying to be lazy and hope that someone would do that research for me! But since you called me on it, let's look into soda ash some more - check out this web site:

    http://www.ocichemical.com/webapp/ociapp/products/prodfamily.jsp

    Check out the second product - the OCI Lite. It is decribed as "OCI Lite? is particularly useful in the production of granular detergent type products where high bulk is desired and the product must remain free flowing in the presence of liquid wetting agents. It is also the product of choice for many water treatment applications..." This is what I believe your pH plus pool chemical is (note water treatment suitablility).

    Click onto the product sheet and there is a list of specifications, scroll half way down the page to the specs and typical assay for "OCI Lite":

    Sodium Carbonate (%Na2CO3) 99.2 minimum 99.80 Sodium Oxide (%Na2O) 58.1 minumum 58.40 Sodium Sulfate (%Na2SO4) 0.15 maximum 0.085 Sodium Chloride (%NaCl) 0.09 maximum 0.03 Water Insolubles, % 0.05 maximum 0.03

    OK - Here we go. That's a little more precise and descriptive of our product than the MSDS. Here's the link to the MSDS for this product:

    http://www.ocichemical.com/webapp/ociapp/products/msds_us.pdf

    The MSDS lists the content of sodium carbonate in the soda ash as "100%", but as we can see from the product specification above, that the sodium carbonate content of this soda ash product, is NOT "100%". In fact, it can be a MINIMUM of 99.2%.

    The manufacter does say that 99.80% is a more typical value though. I want to point out that even though they did not state this, I bet the manufactuer does not worry if they have an assay that is OVER 100% -I bet that they may not sweat getting a 100.3% assay.

    So now note that the choride content for this product has a maximum spec of 0.09% sodium chloride (that's 900 parts per million) - nearly 0.1% . I just looked at a bottle of Mallingkrodt anhydrous sodium carbonate, analyzed reagent (AR) grade, and it is 0.0006% - 6 parts per million. That's quite a difference between these two products. Now that we have some actual, working specifications for this one product, I'll let Ron let us know if this chloride content is significant, photographically speaking.

    Also note the water insolubles - spec'ed at 0.05% - that's 0.05 grams in every 100 grams of the product of what most of us would call "dirt".

    Looking over the specifications for OCI soda ash - the OCI Dense product actually has a slightly lower specification and typical concentration for choride than the OCI Lite product. Perhaps we should be looking to glassmaking factories for our soda ash supplies instead of pool chemicals...

    Also, if you really want to get some of this stuff cheap, read closely to the product specification and you will see that it can be purchased in several different sized containers - 50- and 100-lb. net weight paper bags, Bulk trucks, Jumbo hopper rail cars, and Ocean vessels! ! ! ! You probably get a great deal on the ocean vessel sized lots! !

    Ron and Jay mention using the purest chemicals possible. I would like to point out that this is not really a proper approach either. What is needed are chemicals that meed the specifications for your needs. There is no point in paying extra money to get an "ultra pure" greade of any chemical if you do not need it. It is very typical for labs (and I suggest photographers too) to buy the grade that just meets the specifications for your needs. Grades that do not meets the specs needed may have problems, and grades that greatly exceed you needs waste money.

    Let's look at the specs for photograde POTASSIUM carbonate that were given by Bill C in an earlier thread: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=008Yy1

    Bill gives the ANSI spec for photograde POTASSIUM carbonate as 0.06% (600ppm). Assuming that photograde sodium carbonate has a similar spec to the potassium carbonate, it is slightly under the OCI soda ash limit. If you get a "typical" batch of OCI Lite soda ash, you are probably OK choride-wise (but you may not be so lucky with insoluble matter...)

    So maybe in this particular case, things DO work out - but I think that the point here is that unless you do the research necessary to determine these what your needs are and if the materials meet those needs, you may have some real issues and not know where they are comming from and you may have other issues that you can not even try to quantify.

     
  16. Sorry Jay, I meant Jordan above.
    Sorry Jordan, I meant you...

    Kirk
     
  17. Jordan - you asked specifically about "unrefined" - I didn't mean to imply that the material is what one may consider "unrefined". I suspect it is "minimally refined".

    Even if it is dug or pumped straight out of the ground, there is still some "refining" going on. I think in the other thread I talked about how soda ash (and in my example of the potash mine near Moab, UT) does have some refining steps by using evaporationg ponds to recrystallize solutions of the material. This is certainly considered to be refining.

    But if you mean that there are special chemcial reactions that are being performed on the materials before it gets into the pH plus bottle, I suspect they are really minimal. You know there is no real reason that they can not actually be adding certain chemicals to the evaporating ponds to "clean-up" the product, but I don't really know the details of the process that well.

    One thing though - I'm sure the soda ash is dried to remove as much moisture as possible - to make the material more concentrated for shipping needs. Why transport all that water to China or when shipping it to the pool chem place? If they need water there in it, they can add it! So, there's one refining step that I know is done.
     
  18. Jay;

    Thanks for the kind comment. I'm just happy to help, and I don't think I'm anything special. I've just had a lot of experience in this area. You each have your own area of expertise.

    Kirk;

    Thanks for the lead in. An impurity level of 0.1% of NaCl in a particular developer that I know of, at the level of Sodium Carbonate used as buffer, would just about DOUBLE the level of NaCl in the developer and render it entirely unfit for use. I can't give more details, as the developer is proprietary, but the results would change curve shape and speed drastically.

    I would like more clarification on the Na2O as well Kirk. If that is present in any large amount, the resulting solution would be more alkaline than pure Sodium Carbonate. That could be detrimental as well. The pH and buffering capacity could change from batch to batch.

    Also, in your comment about using pure chemicals, of course I don't mean that one should use analytical grade. You are entirely correct in stating that the purity should be as high as needed for the purposes intended (to paraphrase your remark). My feeling at the start of this was that I had a strong doubt that 'pool grade' sodium carbonate was pure enough for photographic use. A photographic grade chemical is pure enough for me.

    My bottom line though is that Na2CO3 as you have posted above would probably be entirely unsuitable for many developers due to NaCl variations and Na2O variations, as well as the grit introduced by insoluable materials. This would not be the case for all developers but rather would have a different effect on every photographic film and paper to a different extent. If it was consistant from batch to batch, you could work around it, but if not, it would become a real hassle. Someone designing or using a developer from one batch could see a discontinuity if he changes batches. This is what I wanted to warn about.

    Thanks again Kirk for an excellent and most helpful post. You are quantizing the things that I have been trying to make people aware of.

    Ron Mowrey
     
  19. Sorry, but in my previous post, I said that the error would be about double NaCl. I was wrong. It would go up by about 15%. The results would still be nearly as bad for this particular developer.

    Oh, I'm getting old. Thats why I always check my figures.

    Ron Mowrey
     
  20. Ron - you ask about the Na2O content. That's just another way of assaying the soda ash. Actually it is really common in assaying minerals or materials that are made from minerals, such as lime, cement, concrete or rocks themselves. It makes the assumption that the material has been heated up to say 1000F to breakdown any minerals to simpler forms so that they can be analyzed. Especially when working with things like concrete or cured cement, it makes things much easier by doing this. It removes the water (and carbonates in things that contain lime like soda ash) and the material gets much weaker. (Here's something to toot my own horn - you may have figured out that I used to do this type of analysis too. I did. I actually did the analysis on the original mortar that was used in Crater Lake Lodge. It was analysed so that they could duplicate it when the reconstruction of the lodge was done in the 1990s.)

    The soda ash assay had an entry for sodium carbonate content - that assay is probably performed by titrating a known, dried at a specified temperature (maybe 285C), amount of the soda ash against an acid that has a known normality - something like 1.0 N hydrochloric (I'm kind if guessing on the actual normality - it could be 0.5 or 0.1N).

    The Na2O assay is kind of a simplified way of looking at the soda ash - it assumes that you only are looking at the sodium content. This test is probably done on an atomic absorbtion (AA) or an emission spectrophotometer (ES). You dissolve some of the material in water and dilute acid and suck them into one of these big machines. The machine aspirates the solution into either -

    1) an air/acetylene flame and measures the aborption of the amount of light from a sodium emission lamp that is focused through the flame (AA method)

    or
    2) you aspirate it through a plasma jet which rips the electrons off any atoms that pass through the jet and the machine then measures the light given off as the electrons fall back into their orbits (ES method).

    (I used an AA for the Crater Lake Lodge mortars.)

    Once you have the sodium content, you report the result back as the simple oxide form of the metal, e.g. Na2O, K2O, CaO, MgO, FeO, SiO2, MnO... As I said, this is common in that type of industry.

    Actually, you kind of want to worry about the Na2O being present in large amounts - it's really the sodium carbonate there (note that the spec says 58.1% MINIMUM). So it's not something that's detrimental, it's just another way of figuring out an assay of a material.
     
  21. Ron - when does your non-disclosure agreement with EK run out so you can tell us some of the nitty-gritty details on some of these things like formulations and such?
     
  22. Conrad mentions above that he has been pondering things such as microdensitometry. And Ron brings it up as well as a major part of his arguement.

    Does anyone here have a microdensitometer? I know that Dr. Richard Henry used one in his classic book "Controls in B&W Photography". (Side note, this book is a must for anyone that is even remotely interested in the types of subjects that we have been looking into here lately.)

    I would be interested in hearing from someone that has access to one or actually owns one. Perhaps there is a revenue source out there for that person by doing some testing on our home-brewed solutions?
     
  23. Kirk;

    Thanks for the clarification on Na2O. I didn't think it could be there as an impurity for long. You would end up with NaOH pretty darn fast.

    I am really honor bound not to disclose formulas, for anything, but I guess I can tell you that any chloride or chlorobromide paper will be affected by the variations you are talking about. Usual papers use NaCl as one of the antifoggants, and it does not take much to alter speed or contrast. The variation you mention is ~15% in one very common formula at the carbonate level used, and is about 45% for another paper developer which is less commonly used. It would be about 30% in another paper developer formula which has been discontinued.

    Hope that helps.

    On the subject of microdensitometry, I think you can see how edge effects affect sharpness of an image. It also affects the micro H&D curve vs the macro H&D curve. The curve shape you usually plot is a good test for a given film, but if the developer is misperforming, micro tests are needed to quantify the error and diagnose it.

    KI released by films changes edge effects, so if KI is too high or too low, this effect varies. Bromide varies the effects of KI being released by changing antifoggant restraint levels. The pH of the film drops very rapidly during development, and the buffer raises it. If the pH fluctuates too fast or unpredictably you get varying antifoggant rates and varying restraint rates. The ratios of silver complex types and amount are governed by solvation rates which depend in part on pH and silver halide solvent ionization etc.

    Bunch of blather, but what it amounts to is that development is rather complex in films and can be totally upset by rather small changes sometimes, and those changes can be invisible to casual detection methods.

    Ron Mowrey
     
  24. Kirk, you beat me to it! I was going to ask if anyone had or had access to a microdensitometer. I own just about every tool known to man, but I'm afraid that one isn't on the list. Heck, I've never even seen one. For now, all I can do is take great care in printing, and look at details and test targets under a good microscope. BTW, I've found little correlation between what you see under the microscope, and what you get when printing, probably due to illumination differences.
     
  25. The definition I quoted is from the glossary of terms and is the NIOSH definition of inert. You can reach that glossary from the URL I provided. The definition does not say that Teflon is unconditionally inert. Look again. Dihydrogen monoxide by any name is not listed as inert, nor should it be. I don't remember how all this got started, but I do know that every time I try to explain my position, someone else tells me that is not really my position. Phooey!

    Lex, I have been called out about my background. If I may send it directly to you, I will, and will let you decide if it should be made public. Nobody will believe it in any case, but I can provide it if need be.

    Yours in brotherly love,

    Pat Gainer
     
  26. Guys;

    I searched my darkroom and found a set of microdensitometry test patterns. One is negative and one is positive, on lith film.

    So, I could set up to do the exposures somehow. Measurement is now the problem. Unless we just publish the results and let people judge for themselves. I tried scanning and got a moire pattern as I expected. I'm going to try a few things before I give up on it though.

    Ron Mowrey
     
  27. First of all, I want to acknowledge the valuable information provided by Patrick, Ron and Kirk. You are all tremendous assets to these forums and I greatly appreciate your contributions.

    As for these debates I believe they are healthy and make for lively, interesting and revealing reading as well as being of value for those photographers who enjoy the technical aspects of the craft as much as the artistic. I only ask that everyone continues to participate in a spirit of mutual respect.

    My observations on this particular issue are limited to only a couple of areas:

    First, as a former federal OSHA safety and health inspector, I can only say that the purpose of an MSDS (material safety data sheet, for folks unfamiliar with the terminology) are intended only to inform employers, employees, the transportation industry and emergency responders about the potential hazards associated with a chemical or other material.

    Therefore "inert" within the context of an MSDS is not necessarily relevant to the issue of chemical purity for the sake of making consistent compounds.

    NIOSH (National Institute for Occupational Safety and Health) is the research branch that conducts experiments and provides recommendations to enforcement agencies such as OSHA, MSHA (Mining Safety and Health Administration) and EPA. NIOSH is not a regulatory enforcement agency. They are the primary source of information used in the assembly of an MSDS. Again, the focus of NIOSH is safety and health, so their definition of "inert" does not necessarily apply to other disciplines of chemistry. Coincidentally, tho', in many cases the definitions would match because with many materials inert is inert, regardless of context or use.

    For a definition of "inert" as it applies to the purity of chemistry from the standpoint of *application*, one would have to look to the organizations which NIOSH also uses for reference material. There are many and, frankly, this is beyond my area of expertise which was occupational safety and health.

    My second and last observation is casually related to the discussions regarding volumetric measurements.

    When I was younger and had steadier hands I participated in various target shooting sports. Because of the cost I began reloading my own ammunition. Over time I discovered that there was no practical or significant difference between the consistency achieved using ammunition into which gunpowder was carefully weighed using a powder trickler for each charge versus using Lee's yellow plastic powder dippers.

    These dippers were relatively long and narrow - totally unlike a typical set of kitchen measuring spoons - and the design facilitated consistent results. Using the dippers involved simply dipping the measure into a bowl of gunpowder, tapping the handle to level off the overfill and pouring the powder into the brass cases. The trick was to develop consistency in leveling off the measures. For example, scraping off the rounded overfill using a flat edge was not good because it could compact the charge resulting in inconsistencies. A simple tap of one finger or sideways shake was best.

    It sounds rather crude compared with weighing each charge yet differences between the two methods were insignificant. I got the same accuracy in grouping and my chronometer confirmed that both methods produced equal results.

    The difference is that weighing charges required no skill whereas using the dippers required some skill to produce consistent results. This was especially true because gunpowders vary between large and small flakes, tiny BB shapes and shapes similar to broken pieces of pencil lead.

    So my personal experience indicates that volumetric measurement is valid, otherwise I would not have risked blowing up my gun or myself if I believed the method was significantly inconsistent.

    My experience mixing developers from scratch is extremely limited and only moderately successful. I hadn't even mastered the art of choosing compatible ingredients so I doubt that my use of kitchen measuring spoons was as significant a factor as my ineptitude at mixing coffee, lye, etc., into a workable solution.

    Take with a dose of salts.

    (BTW, the correct original expression, "dose of salts", refers to a dose of laxative. IOW, it means be careful taking advice because the advisor may be full of s__t.)
     
  28. I have been following these discussions for a while, and I found it funny that Lex brought up one aspect I have been thinking about too regarding volumetric measurements, the Lee dipper!

    Gunpowder is rather uniform in consitency compared to many chemicals discussed in these trads, so i would say the comparison is not entirely valid. In measurements one refers to precision and accuracy as two different things. Precision is how close you come to the correct value, and accuracy is how close your measurements are in reltation to one another. Think about target shooting. Good precision is hitting the bullseye (your average point of impact is center). If you have good accuracy, you might not hit the center, but your shots are very close to one another.

    For instance; i have a teaspoon that might differ from your teaspoon in shape and size (teaspoons are not standardized!) If we both are accurate about our measuring technique we may both have good accuracy, but we may not measure out the same amount! Think about it, it should be pretty obvious.

    back to the Lee measure; it is supplied with instructions on how to measure, the Lee measure is standardized, and the charges it throw are conservative for safety reasons.

    I am an active bench rest shooter myself (bench rest is all about extreme accuracy, the formula one of shooting sports) and the whole world elite and myself use volumetric measurement of the powder for reloading ammunition. Let me tell you, if it was found to give an advantage by weighing the powder, everyone would soon be doing it. We all still use powder measures for short range bench rest (out to 300 meters, long range shooters weigh... there it definitively matters for reasons not interesting to this forum).

    I shold also inform you that i am an organic chemist, and for all my scientific and photographic work I weigh. I do not use teaspoons, rely on manufacturers packing and which crystalform whatever chemical is in. I weigh, often taking precautions to remove absorbed moisture etc.

    So for me, which method I use depends on the intended purpose. If you want to experiment and KNOW what you are doing, you should weigh. Otherwise it is a qualified guess, not a known amount.
     
  29. Ron - so no nondisclosure agreement. That's interesting...

    Conrad - great minds think alike! Although if we did find someone with a microdensitometer, to use it would probably require a whole different level on our part in our testing procedures to get accurate and repeatable results from it. It also would mean that we would have to repeat tests on multiple occasions - all the sort of stuff that Ron could tell us about that go into testing a new developer. Perhaps that would be a good article or at least a new thread...

    I looked over my Henry book last night and he had problems finding an actual microdensitometer and ended up adopting a Zeiss microscope, hoioking it up to a computer that controlled the position of the microscope stage, and a photo multiplier and a Zeiss data acquisition system to collect microdensitometery readings. I actually have a friend that does microchemical analyses and Zeiss and Nikon scopes are his primary tool. He also has a high-end digital camera connected to the scope. That may do it! I guess I need to check with Ron about the masks that he mentions below.
     
  30. Patrick, I did look at the web page you provided and even looked around the glossary and the rest of the site some as well. (And I assume you looked at the ones I provided too). I'm still not convinced about this site having the "NIOSH Definition", and that site is not even NIOSH or US governement web site.

    The site does not give a reference to any Code of Federal Register (CFR), where all goverment regulations are recorded. You may have noticed the US Department of Transportation definitions I gave above supplied CFR references.

    Go to the home page of the web site you listed and you will see they would like to sell you the domain name to US$3450. And the link you give actually comes up trying to sell you a domain name for US$59 - that's not even a very good deal. I did find the pages you reference, but I had to find it through google. I know it is hard to find stuff on US governement site - the EPA site annoys the hell out of me sometimes. But this site is not an authoritative site.
     
  31. Patrick, I'm familiar with your credentials, at least as far you've stated them in your PhotoTechniques articles. You are a retired aerospace engineer that worked with NACA/NASA. That's cool! If you would like to supply more info than that, I would like to hear it.

    I'm also familiar with your articles - they are some of my favorite ones that I've read in PhotoTechniques.

    I'm not on some personnal attack as I'm sure you are not as well, I just want claims to be supported by proper references. I think we have far too many unsubstantiated claims made for many things in these types of forums.
     
  32. Lex - that's for giving your input on the proper uses of MSDS sheets.

    You and Anders both mention that for high accuracy, long distance shooting that wieghing is the preferred method of measuring out gunpowder. I suspect that is precisely because it IS more accurate and the distance shooters need that extra accuracy. Small variations in the amount of charge probably do not have the time or distance to be very noticable when shooting at targets that are at shorter distances, but when long ranges are involved, and longer times of flight involved, it sounds like that variation does become noticable and thus wieghing becomes the preferred method. Is that correct?

    So it is again when we are looking at the fine details that these affects become appearant - which is been the main contention that Ron and I have been making.
     
  33. Kirk;

    The unsupported claims and myths are what started me as well. I want to have statements supported by facts.

    My charts are resolution charts that can be adapted for microdensitometry.

    My comments here and elsewhere about micro densitometry come from a chapter of Mees, "The Theory of the Photographic Process" called "The Structure of the Developed Image". He gives three definitions:

    1. Sharpness is the property of a photographic material that leads to pictures having good screen definition. It is a subjective concept.

    2. The term acutance is the objective measure of sharpness.

    3. Resolving power is the maximum number of long parallel lines that can be distingushed separately and does not correlate well with sharpness.

    Too many talk about 1 and 3, but not enough about 2. The actual response of a photographic material is subjective, but is always related to 2, and rank ordering by viewers of subject material always results in following the values calculated by 2.

    He also shows values of density that vary from 1.7 in 1 micron lines down to 1.4 in 100 micron lines at identical light intensity and time, showing the change in curve shape due to edge effects or the micro contrast of a subject material. Included are the effects of contrast on subjective and objective evaluation of all 3 above.

    Kirk, I did have an agreement with EK. It expired a few years back, after I retired. Now, non-disclosure is really an ethical issue with me. I know that some would argue this point with me, but I won't change. I will not disclose proprietary formulas. I can give general suggestions, but not precise information.

    I would like to direct you all to a similar thread by James Dainis on color over and under exposures. Fascinating, as Spock would say.

    I too load my own shells using volumetric measurments. I'm not a bad shot but am deteriorating due to eyesight and tremor. I use volumetric backed up by quality checks using a powder balance. That insures uniformity. I have my Lee dippers calibrated for all forms and types of powder I use for rifle, shotgun, and pistol. The difference is that, as pointed out above, powders are uniform, and therefore errors in volumetric measure are small. If you look at velocity tables, you will see that there is a range of powder rates associated with a given powder in each book such as those by Lyman and Lee. None of the books I have read seem to agree on velocity vs powder measure. I stick to one powder, at one rate, and one bullet weight, for a given calibre and do pretty good.

    Regards.

    Ron Mowrey
     
  34. Here I use .44 lead balls; blackpowder; patches; and measured by the volume loads. Fooling with different patch lubricants and patch thickeness is a huge variable. What is all this reloading of brass for?:)
     
  35. Let me take what I hope is a different tack. It has been expressed by at least one other in this thread that there is no point in spending money for analytical grade of any chemical if you know that a lesser grade will suffice. we have heard that for at least one emulsion-developer combination guarded by trade secret that a miniscule amount of chloride will ruin a batch of results. We have seen that an assumption of anhydrous when pentahydrate was intended caused a problem.

    If the problem with chloride content exists with a secret, how are we to know to avoid it? I rather imagine that if it is made available to you and me, it will be as a combination anyway. We won't even be tempted to duplicate the results by teaspoon measurement of tech or commercial grade chemicals.

    Chlorine content of water will use up a considerable amount of ascorbic acid or its isomer, as will dissolved or entrained oxygen. In any of the developers I have proposed, these are things to look out for. It takes a lot of chloride to change the characteristics of a film developer. Trace amounts will not do. So what are we who do film and chlorobromide papers worried about? Nevertheless, I never advised any one NOT to weigh chemicals.

    If we agree that we do not know the precise assay of the sodium carbonate in pHPlus or other commercial grade, how much more likely are we to know that it is not exactly the same as we buy for photo grade when the precise assay of that grade is not made known?

    If we want to argue, let us argue about proper means of testing that we might use in our own darkrooms (or kitchens). It seems that many of us are not inclined to trust NIOSH specs or any others. In that case, it is pointless to weigh out milligrams of a chemical when we do not even know what it is. It seems that I am digressing again, but read on.

    My background is 70 years old and will take quite a few words just to hit the high and low points. I always had an interest in the physical world and the metaphysical world. I studied chemical engineering for 3 years, then switched to aeronautical engineering. All the time, I was an amateur photographer and an oboist of sufficient ability to be first oboist of the University-Community Orchestra and later of the Peninsula Symphony of Newport News, VA and of the Norfolk Symphony of VA which later merged to form the Virginia Symphony. Upon graduation with BS in Aeronautical Engineering, I was employed by NACA at Langley Research Ceter to do analysis of flight test data among other things. Without moving from that desk, I later became employed by NASA. One of my first tasks was to design star charts for use by Mercury astronauts as emergency reference for reentry alignment. By the time of my retirement in 1982, I was doing human factors (see "Cheaper by the Dozen") research into piloting tasks. When I retired, my position statement described me as "an internationally known expert in non-linear mathematical modeling of the human operator." Go figure. We did what had to be done. Our group assigned to any project might have mechanical, electrical and aeronautical engineers, mathmeticians, physicists and anyone else who might be needed. We learned to talk to each other.

    Now if we are concerned about the subject at hand, which is how to know what we need and how to know if we've got it, my tendency would be to have a task group of varied experience to work on it. I know the old saw about things formed by committee. This is not a case of voting to accept opinions, but of finding facts and making them known.

    We have the problem of not being in personal contact with each other. That is a valuable condition. Many things that are written have a much different context than the same things spoken face to face. You and I cannot see when the other is smiling or frowning. Believe me, I enjoy smiling much more than frowning.

    Enough. maybe too much.
     
  36. LEX and the group Re: Therefore "inert" within the context of an MSDS is not necessarily relevant to the issue of chemical purity for the sake of making consistent compounds.

    The MSDS sheets can have other things besides chemicals. The MSDS sheets for lamination film has NO chemical warnings; BUT it lists one big problem; busting ones rear on the CLEAR scraps of finished hot lam film; that miss the trash can. One can slip and fall real bad on the clear scrap; which is generated in the course of business at a print shop; school; photo lab. When one is laminating several hundred feet of film a day; one lone scrap the size of a credit card will cause an person to fall.
     
  37. In read write heads; the slider/heads are cut out of wafers; made up of layers; like an IC chip. If some of the purity of the solutions used in plating is too low; the head can degrade with time; but pass all specs when made. This time bomb causes the heads to drop in performance; and is abit rare. Once we had a major customer who had data rot; and we traced it back to the certain wayers used by vendor B. What a mess.
     
  38. There seem to be a lot of shooters here, myself included. Advice of the day- If you're going to carry a gun and a camera, double check to be sure you've grabbed the right tool for the job at hand!
     
  39. Kelly;

    In certain read write heads, the laminates are embedded in ceramic. The cermaic for a certain company had a very tight spec, but didn't include entrained air bubbles. As the head wore, the ceramic did too, and the bubbles were exposed and became 'ice cream scoops' as far as the diskette was concerned.

    In double headed drives, this scooped out the medium right down to the transparent support. The manfufacturer learned a hard lesson.

    Patrick;

    I agree, lots of things cause lots of problems, for example ozone in some European municipal water systems will consume ascorbic acid differntly than chlorine in US water systems. Varying pH of water systems also affect solutions. You say that one formula that is proprietary and therefore not hand mixed may have a problem.

    Well, here is an answer. In my short tenure here, I have seen at least two references to hand mix formulas on other sites for this developer, both wrong, btw. In recent months, several people have made reference to this particular formula and the fact that they were hand mixing it. If they had used your method, using swimming pool chemistry, and if Kirk Keyes comments about NaCl impurity was correct, then they would have problems with the formula.

    I never said that anyone should stop using the methods or chemicals that they were using. I just pointed out the potential faults and problems inherent in some methodology and useage. Kirk and others have done the same. I repeat here, if it works for you, use it, if you are satisfied, keep doing what you are doing. If you read my posts here and elsewhere, I have said this repeatedly.

    Just as you have stated, and I paraphrase, others are misquoting me and attributing statements to me telling me what I said and meant. What I said and meant can only be derived from what I write.

    I added however, that our current 'eyeball' methods of evaluation were sometimes inadequate to the task of determining the quality of our results in photography. I added though, that if you like it, then that is sufficient. My reference to Mees describes some of the pitfalls though that escape us in qualitative measurments.

    I have not even delved into the tanning effects on gelatin by certain developers, the cracking effects that degrade images using some developers, and etc. This is a huge area involving complex interactions.

    I would not think of giving you advice on deriving star charts. Just please give Kirk and me for that matter, and some of the others who are chemists and photographic engineers the benefit of a doubt when we give advice on potential problems.

    While you were deriving those star charts, I was at Cape Canaveral telling the astronauts how to take pictures at high altitude and in space, and giving them the UV filters to use with their cameras.

    While you were working for NACA, I was flying high altitude intelligence gathering missions in the back seat of jets as well as working on the ground. I was certified to fly up to 100,000 ft, hence my UV filter knowledge. I also carried a rifle and pistol when the situation warranted it, and I lost two men under me. I have great respect for human life, having lost two young men who worked for me.

    All of us, when we reach this age (I'm just slightly younger than you) have great respect for the wisdom of others, and should respect the fact that others may have knowledge that we do not and that we can learn from and profit from. Kirk is teaching me a lot I never knew, but just had as qualitative information. I cannot presume to teach him in his area of expertise. I do listen to his advice. Same with Lex.

    OTOH, I cannot just dig into my personal cache of proprietary prints or data and throw them out here. In the first place, that cache of prints and data were the property of EK and were left behind. All I can do now is either repeat them personally and post them, or tell you general facts about my old data. Also, I must draw on my color experience as that represents over 80% of my work. However, the analogy to B&W is there, and I can draw on it to point out possible problem areas.

    Warmest regards to you all, and thanks for the very good contributions.

    Ron Mowrey
     
  40. Well, Ron, if you are talking about the Mercury, I must say I was sitting at my desk wondering why in the world they were trying to take UV photos through the Mercury window when the UV spectrum that came through was not as broad as what we see on a clear night. They had special lenses that passed all the UV that you could want, but none of it got to the lenses. They could not see any stars of magnitude >6.

    Some of these things were funny. Others were not. When Scot Carpenter came to inspect the star charts, he couldn't resist sliding down our wide banister on his way out. When he used up almost all of his maneuvering fuel gawking, that was not funny.

    I still haven't seen a response to the question "How do we know what purity we want, and how do we know when we've got it?" I see Arm&Hammer baking soda, specified USP, cheap as dirt. It would be cheaper to heat that into the carbonate than to buy so-called photo grade of unspecified purity. But do we need to go to that trouble?
     
  41. Ron; I was given the task once of how quickly to destroy a hard disk drive's contents. At that time; computers were disassembled; and the actual disk platters shredded in a aluminum chipper. One method is just to fry the thing in a oven; above the curie temp of the platters magnetics. The plastics and no metal parts creat a mess. Certain chemicals quickly mess up the platters; and do the job quicker. Coated disks create a problem; sometime a crusher is the easier; cheaper method.
     
  42. Patrick;

    You misunderstood, I think. The Astronauts were taking color pictures out of the capsule window, not UV pictures. They wanted to filter out the UV and they wanted to have information on the EK UV series of filters which I used to use in high altitude photography.

    At that high altitude, UV radiation is significant even through their window. At least that is what NASA told us. EK designed a film with thin support for the flight so that they got more exposures / roll as well, and the film was tested in vacuum to determine if evaporation of residual solvents caused any problems. I worked with both EK and NASA at that time in my position at CCMTA.

    As for your answer on sodium carbonate, or indeed any chemical, I use photographic grade. I stated that in the original thread, and I rely on the distributor to supply me with such chemicals. If they don't, the onus is on them to make amends with me. So far, they have not let me down. Now, they may very well be supplying me with soda ash, and by Kirk's definition I may be getting floor sweepings, but that is between me and them if I should have a problem.

    Kelly, at EK we used observed crushing for hard disk drives containing confidential data. IBM honored their warranty on drives if we returned a crushed disk drive to them for warranty replacement as long as the IBM serial # was left intact on an uncrushed surface of the drive. I was the research member of the EK team that helped negotiate that little detail.

    We had a joint computer security task force that met on a regular basis at EK or at IBM Rochester HQ.

    Ron Mowrey
     
  43. Ron, Patrick,

    I do have some suggestions about making your own carbonate out of bicarbonate, but I have to go to sleep now and then it's off to the historic races tomorrow so I'll probably have to wait until Monday to make them.

    By the way, I was in the first grade when Niel Armstrong stepped onto the moon, so I envey both of your involvment in the space program. I'm just a 41 year-old analytical chemist that had the extreme good luck to start out in a lab the did specialty testing and I ended up being the guy that got to research methods and then do all the odd-ball samples that came in for about 4.5 years. It was an excellent way to begin a career as an analytical chemist.

    Patrick, did you work on the charts with the 3 famous stars Navi, Dnoces, and Regor on them? I know that was Apollo, but if you were involed with that I'd love to hear about anything that you would like to comment on!
     
  44. Ron,
    I didn't really think you would have been involved with that mess, but it did happen. Whoever at NASA told you there was significant UV getting through the window had not studied the matter. The window was IIRC about 1/2 inch of window glass, albeit high quality. The transmission density of it was actually measured to be about the same as the atmosphere. We had to know that for our star charts. There might have been enough UV getting through to upset color balance, but someone else (I know not who) designed and had built a special Hassy with a lens specifically designed to transmit and focus UV, thinking that here was a chance to photograph a part of the spectrum we cannot see down here. While it is true that they were above essentially all the atmosphere, the window negated all the expense and effort that went into the camera. It was not until Gemini and EVA that they could use it. I think the lens was constructed of Germanium glass, but won't swear to it.

    As to what stars were on the charts, it depended on what part of the sky would be visible within +- 20 degrees of the orbital path. My job was to set up transformation equations from Nautical Ephemeris tables of right ascension and declination to orbital path coordinates. I had plenty of help entering data from the ephemeris, programming the equations, and plotting the charts. A genius in the analytical computing division used the high speed line printer to print symmetrical characters (o, x etc) where stars should be on very wide paper. Our office people put black circles over these characters of size according to star magnitude. There was a different chart for each possible 15 minute launch window. The large charts were reduced and printed on special plastic and equipped with a time scale and a cursor that showed the outline of the Mercury window to scale. When the cursor was aligned with the time scale at time after launch, the cursor showed the star pattern that should be seen in the actual window if the capsule was properly oriented for reentry, with sufficient accuracy to pervent burning up.

    We could do that whole task up to the final construction with the personal computer and printer I have in front of me. We still had electromechanical calculators for matrix manipulations. There are other stories about that.
     
  45. Quartz glass is sometimes used to pass UV; in bulbs; lenses; cylinders in UV printers; etc.
     
  46. Our high altitude cameras looked out through glass windows that were transparent to UV, and the higher we went, the more filtration we needed to eliminate the UV blue shift and haze. EK made a series of special filters that went above the normal UV series 1 and 2. They supplied us with a 3 and 4 filter set for 50,000 ft and 100,000 ft. I talked to two of the astronauts about this as they were concerned that on the first flights the pictures were too blue due to UV and had too much haze, and wanted to know how we did it with high altitude photos. That is when I was called in to talk to them and bring them filters.

    Every can of Aerial Ektachrome was supplied with a package of filters in the can to fit over the lens of our camera. I still have one unused set.

    The person who did the camera work was Roland (Red) Williams. I have a picture of him with the astronauts with the Hassy, and another picture of him with me in front of Liberty Bell 7, with Glenn's capsule in the background. My mother cut the picture of Red with the astronauts out of the newspaper and sent it to me, the other one was taken of us about the same time as the newsphoto was taken. They didn't publish the photo of us though. I wasn't news, so they gave it to me.

    I have a little box of discarded parts from Red that failed to pass muster for the Hassy. The film advance was not right for the glove, etc, etc. Red would machine them out of aluminum and replace parts with the lighter weight stuff. He replaced stainless screws with aluminum screws and drilled holes in the frame of the camera to lighten it up.


    Ron Mowrey
     
  47. I should mention that I was never officially a member of the Space Task Group that started at NASA Langley Research Center. Somebody recommended me to Robert Voas, a human factors type and head of the group, for the star chart job. I had a chance later to relocate to Houston, where many of my friends had gone, but decided I had too many interesting things to do in Virginia.

    I never met Red Williams, and don't know if his project involved intentionally photographing in the UV. From what you say, Ron, it may have been another project, and it may in fact never have lifted off if they tried to take UV photos through the capsule window on the ground. I can't imagine anyone of us designing a camera specifically to record UV images and then putting a 1/2" thick piece of flint or crown glass in front of it. As I said, we found that stars dimmer than 6th magnitude would not be suitable for the star charts because the window would not let them be seen. I seem to remember that the optical density of that window was about 0.4.
     
  48. Patrick; No one ever mentioned in any way photographing in the UV. All they talked about were taking color photographs through the capsule window. They took several rolls of 120 film on thin support and all of the astronauts took pictures from orbit using the then existing color negative film. I have no idea whether they ever used the filters that I gave them. I only got involved in that part of it after about the first 2 manned launches, although I worked on all of them until I left in August of '62. Our crew was the last to sign out of the gatehouse at the pad for Glenn's launch, and we were the first to sign back in. The cameras that I saw had normal lenses, but had vastly altered bodies due to new winders, focusing rings, and lighter weight chassis / body with holes in it. Ron Mowrey
    008ono-18731584.jpg
     
  49. MSDS contains the most basic information of a chemical, as well as a the safety data. Any information that you need but unclaimed on the sheet can be asked for from the manufacture. Take Lithium Aluminium Deuteride for example, it's attached with the MSDS file. Almost every safety related data is contained.
     

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