
StarBright User Manual
91
12
Special Sensors
In addition to the Thermopile, Photodiode, and Pyroelectric sensors described in the previous
sections, Ophir offers sensors that are based on similar technologies that are geared towards
other measurement applications.
Topics include:
12.1
BC20
The BC20 is a scanned beam laser power meter that is based on a Photodiode detector coupled
with innovative circuitry to measure scanned as well as static beams.
Based on this Photodiode, the BC20 has the same dynamic background subtraction as the
standard PD300 which eliminates over 95% of background light and allows measurement in
normal room light.
Differences between BC20 and Standard Thermopile Sensors
Although BC20 sensors are Photodiode based, they are defined to behave like Thermopile sensors
except for the following differences:
No BC20 sensors support Energy.
All BC20 sensors support the Continuous mode. In this mode, the reading displayed is updated
3 times per second with the max power reading of the previous 1/3 second.
Some BC20 support the Hold mode. In this mode, the display “holds” the highest reading for
up to 5 seconds If a higher reading is measured before the 5 seconds have elapsed, the display
is updated and the 5 second counter is restarted.
Figure
12-1 BC20 Screen Layout