Pen F Light Meter

I just picked up a couple of Pen F light meters. Both work, but I was

wondering if someone could clarify the operation. The button on the right side

obviously turns the meter "on". But it appears to have a dual function.

Pushing it half way in takes the reading, pushing it the whole way in is the

battery check. Is this correct?

On one of the meters, the needle is stuck half way in and it is always on.

This is actually kind of convenient. On the other meter there is about a one

stop range of uncertainty between when the meter first reacts and when it

obviously swings to the battery check. Is this typical? Do you just have to

develop a "feel" for where half way really is?

One final point. The shutter speed number on the meter does not line up

exactly with the arrow when the camera's shutter speed dial clicks into its

detent. Can this be adjusted?