OptoTest OP831 Instruction Manual page 7

Definition of Specifications
Spectral Responsivity
Depending on the detector type, InGaAs (Indium Gallium Arsenide) or Silicon the spectral
responsivity, the efficiency of the detector to convert optical power into electrical current
changes with wavelength.
Responsivity of InGaAs Detectors
Note that other detector types are available such as IN5 (5mm InGaAs) IN10 (10mm InGaAs)
as well as WSR (wide spectral range) and might exhibit a different spectral responsivity.
Absolute Accuracy
The absolute accuracy specification includes the total measurement uncertainties
involved in the calibration process including the transfer of the absolute power standard
from N.I.S.T. Contact OptoTest for the detailed chain of uncertainties.
Optical Power Meter, Channel Performance
For multichannel instruments, the power meter circuit converts and digitizes the optical
power level with the given sampling interval. Changes in light levels such as modulation
will be averaged within that sampling interval.
Instrument, Warm up Time
Optical power meters, in general, do not need any warm-up time unless the instrument
has to acclimate to a changing environment. In order to calibrate the instrument or to
perform stable measurements, the instrument should be acclimated for 15 minutes for
each 5ºC of temperature differential. For example if the instrument was stored at 18ºC
and brought into an environment of 28ºC the instrument should be allowed to warm up
for 30 minutes.
Responsivity of Silicon Detectors
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OP831