Is there a reason why you need to calibrate the system each time you restart the software?
Could you calibrate it once for each type of test and remember this next time the software is run?
@Andrew The calibration step is really to get a zero or bank absorbance reference measurement. With a firmware modification it would be possible to store this value in eeprom and re-use it. We decided not to do this for a couple of reasons. The zeroing step doesn't take very long and is standard procedure. For example, different cuvettes can vary in thickness, path length, etc.
I can see how storing the zero/blank value might be useful if you are the only person using the colorimeter and can be really certain of your zero value from use to use. I don't think adding this would be too difficult if you wanted to try.