I just got an Analyser Pro. I've used it to make a few prints. It's a great piece of equipment!

It seems to be about 90% on the spot, right out of the box but, now that I've had some time to experiment, it's time to do the calibration. I've got a couple of related questions about getting set up and using it.

1) Getting it calibrated.
2) Using it to make burn-ins.

I understand the steps on how to calibrate it and use it but, in order for me to best wrap my head around how to use it, I'd like to know more about how it works. Specifically, what goes on inside it's electronic brain.

Question #1 - Calibration:

When you calibrate the Analyser Pro, you are basically making 7 incremental test strips, one for each contrast grade. Then you make 7 contact prints of the step wedge, one for each contrast grade. Once you make and develop those 14 strips, you compare them to the color chip and create a list of offsets which are entered into the analyser's memory.

So, when you do all this, you essentially created a lookup table that the microprocessor uses to calculate exposure times, based on the densitometer readings you make under the enlarger.

Am I right, so far?

Question #2 - Burn-ins:

Assuming your calibration is all set, as above, when you make an exposure, after you press the "expose" button, that exposure time is stored in a temporary memory location. Now, when you alter your time setting and press the "focus" button, followed by the "expose" button, the microprocessor subtracts the time on the display from the time in the memory to get the "difference" time in order to make the burn.

Am I still on track?

Now, if I understand correctly, the time changes that occurr from altering the contrast setting come from the lookup table we created in Question #1 above. Right?

So, to follow that up, let's take the classic example of the landscape photo where the sky needs to be burned at a different contrast than the foreground: First, I burn in the ground at one exposure and contrast. Then, what must I do in order to burn in the sky at another contrast?

My understanding is that you make your alterations to the time and/or contrast and the microprocessor performs the calculations via the lookup table to get a new time. Then, when you press "focus"+"expose," the "diff" time is calculated from the last time stored in temporary memory.

When does that time in temporary memory get lost or altered?
Is it updated when you press "expose" again without pressing "focus" first?
Or, does it stay in memory until you press "X" to clear?