Photometric error?

Question

Hi
This has to do with spectrophotometric analysis. can someone tell me what is meant by the lowest photometric error and why it is important to work in the 0.2 to 0.7 absorbance range for a single beam instrument?

Thanks!!

Answer 1

Photometric error is the error due to your spectrometers light source and detector system (as apposed to electronics noise, calibration errors.

The reason to stay in the mid range is that with too much absorption you have low light signal (creating photometric noise) and with too little absorption you have very little information about the sample.

You want the concentration of the sample to be high enough to "see" absorption, but not so high as to "block" all the light.

Answer 2

depends on what type spec you're using, and what you're measuring. most single beam instruments are tunable and once you take a blank you can see where the most error lies. Read the manual