Beseler PM2M Color analyzer question

I just picked up a PM2M Beseler color analyzer -- I have an simpler model made by Beseler so this is an upgrade. The question I have is the meter probe aperture on this model is supposed to be cosine corrected. I don't know if the small handle should be straight up or the handle pointed to the center axis of the enlarger when taking a spot reading and is there a specific direction when using an average meter reading. Any explanation would be appreciated.
It seems it is totally closed when pointed downward, I presume this if you are going to turn on the room lights.
Thanks

I have a Beseler color analyzer. I believe it is a PM2M and may have the manual. I'll look as soon as I can and let you know.

Sorry, it is a PM2. I looked for info for a PM2M online and didn't find anything. Are you sure about the model.

Yes, it is a pm2M model. It has the photo-detector in the housing with a fiber optic probe. So the probe itself is very small and was supposed to be corrected with the angle error when measurements are taken.
Most have the photo-detector in the probe which makes the probe itself much larger in size.