Re calibration is recommended for ganzfeld type stimulators; a calibration file is created at the time of manufacture. Re calibration is recommended yearly. However, it is up to the end user to decide if they wish to order a recalibration service.
The reason a calibration needs to be redone is due to the degradation of the light source inside. These light sources degrade over time due to temperature and usage. There are a few types of light sources in the Colordome. LED's are found in all colordomes, and are used for most all protocols. Xenon bulbs are found in some colordomes, and emit a short white flash. UV type diodes are used for colordomes in some research settings.
Diagnosys does not provide usage hours like many TV manufacturers provide. Unlike TV's, which are run at consistant lumanaces, Colordome's are run at a variety of flash intensities. The LED's will degrade variably based on how the end user operates their Colordome. Any color of light, at luminances ranging from 10^-9 cd/m2 all the way up to 10^3. Due to variable usage, a standard number of usage hours before recalibration is needed can not determined.
When making a new calibration, we create a file that contains a new calibration curve to ensure that when the software asks for a certain flash luminance, the stimulator is producing that luminance.
A calibration process requires removing the ColorDome or ColorBurst from your facility and shipping it to Diagnosys. Diagnosys will have the stimulator for about 2 days before sending it back. With shipping time on either end, the total calibration process lasts about 1 week.