Weighing chemicals: What scale do I buy?

I want to start mixing my own chemistry (I.E. Kodak D-23) and want to know what

kind of scale I should buy. I�d like to keep it inexpensive so a true lab scale

seems out of the question. I have seen pocket scales that measure to .01gr. Are

these any good? What should I look for in a used lab scale? What are some brands

I should keep my eye open for. Pretty much what scale would you buy and why.

David,

 

like you, I wanted a scale for making up my own darkroom solutions, and bought a small, inexpensive digital scale that is accurate to .1g. I quickly found that this level of accuracy doesn't begin at zero, as I began weighing out phenidone, and the scale didn't register any weight until over 1g had been loaded. I was subsequently given a very expensive lab scale that measures accurately to .01g over its generous range, but I still use the little digital scale for some things that don't require absolute precision, and keep the weights in the range the scale can measure accurately.

 

If you're on a budget, but want to try making up some developers from scratch, I recommend Pat Gainer's ascorbate developers, for which he gives teaspoon measurements. You can find that info at unblinking eye.com. Good luck.

 

Jay

For those tiny measurements, I'd recommend a powder measure from your friendly local gun and sporting goods shop. For everything else, the cheap digital scales, or maybe a used dual pan "Harvard Trip Balance" would be the ticket.

Thanks Jay and Conrad, I geuss you do get what you pay for. I was actualy thinking of using my Powder Scale (my other hobby) but was kind of turned off with converting grains to grams. That being said those nice Digital Powder Ccales can read in both...

I found an Ohaus Cent-o-gram on that auction site for $33. This scale works great for photographic purposes. Goes to 0.01g.

Ohaus has a small, battery-powered electronic scale that's very good for smaller amounts of chemicals (up to about 100 grams). I got one a couple of years ago for about $40. It's good for 0.1-gram amounts and it's good enough to do it with great accuracy. It drops to 0.2 grams above 50 grams.

I don't know what the situation is in the rest of the world, but here in the UK you can buy "smoker's" scales for as little as 12 pounds (about $17 US). These mainly weight to around 300 grams with a resolution of 0.1 grams, which is fine for most developer formulae. D23 uses Metol and 0.1 grams is sufficiently accurate.

 

However, if you think you'll ever want to make up a Phenidone formula, then you'll want a scale with a resolution of 0.01 grams. These are also available quite readily, but generally cost a little more, and only weight up to 50 or 100 grams. BTW, you can double the maximum rating of most electronic scales by using the "Tare" function.

 

Beware the auto-off function, though. Some of these scales have a nasty habit of switching off after 30 seconds, unless the weight changes drastically. This can be a pain when you're carefully trying to weigh out a chemical, and the LCD screen suddenly goes blank. I overcome this with mine by giving it a poke every few seconds to make the display change by a few grams.

 

Despite the euphamism of "smoker's scales", I think we all know what these small pocket scales are really intended and used for. It's a sad reflection that these useful little scales can be mass-produced for an illicit market, while photographic scales are almost extinct these days.

Dear Pete,

 

You mean... oh... yeah... like, wow... Half a weight of hypo, please...

 

I have a set of these somewhere (bought as a photographic prop, I hasten to add) and don't find them very useful: they're about as wonky as their users' perception after a few good tokes of Afghan opiated black.

 

Instead I use an old lab balance, liberated from a school that went over to digital weighing (as most have). Frightening numbers of these have ended up in skips (dumpsters) but an inquiry at a nearby school may still be fruitful.

 

Cheers,

 

Roger (www.rogerandfrances.com)

Hello everyone. Downsizing years ago for retirement, I solded my triple beam scale (4 lashes each day for that blunder!) but recently purchased one of the 0.1 gram electronic scales. Yes, it did have the "problem" of requiring >1g to register. Work around this by getting a thin piece of metal and file it down to exactly 1g. Put the metal into the pan/tray and zero the scale. Any chem's added will show instantly at 0.1g. Enjoy, Bill