Is WS-CRDS really calibration-free?
Contrary to some claims, WS-CRDS does need some type of calibration. However, these are generally very straightforward compared to other optical techniques… The molar absorptivity or extinction coefficient, must be measured and calibrated for each target gas. This is done by Picarro during the development of the spectroscopy for each instrument. These are factored into the spectroscopic fitting algorithm programmed at the factory and never require customer calibration or adjustment. Large changes in background concentration and operating pressure changes can cause pressure broadening effects that must be calibrated. We calibrate these effects, and our spectroscopy routines account for these affects. These are factored into the spectroscopic fitting algorithm programmed at the factory and never require customer calibration or adjustment. Depending on the application, periodic measurement of a known standard may be required for verification purposes.
