Do Scintillation Probes need to be calibrated? Posted on April 18, 2018September 21, 2018 The assembly of our scintillation probes is hermetic, so there will be no degradation over time due to the crystal, unless the entrance window is broken. There could be a change in calibration over a long period of time due to a slow burn in of the PMT. The odds of any failure in the long term (10 years or more) would be due to dropping the probe or some other unfortunate destructive event. However, you will need to calibrate your detector with whichever device you are connecting it to achieve optimal accuracy.