OPHIR vega User Manual page 94

Ophir power/energy meters with the Broadband, P or PF
type absorbers are individually calibrated by laser at
several wavelengths against a NIST calibrated standard
meter. The meter can be switched to give the exact
calibration at the various wavelengths (532nm, 1064nm
and, where applicable, CO2). Since the sensitivity
changes little with wavelength, the user can use the
settings closest to the calibration wavelength with little
error.
The EX type detector is calibrated in the UV at 248nm to
cover the entire UV range from 193 to 400nm.
9.1.2. Linearity and Accuracy of Ophir Thermal Sensors
9.1.2.1. Linearity
The linearity of most Ophir thermal detectors is specified
to be 1% over the specified power range of each
particular instrument and is tested by Ophir from time to
time. The linearity is generally tested against another
sensor that has been NIST tested for linearity. For those
models for which the linearity is not tested over their
entire range, randomly chosen sample models are tested
periodically over their entire range. The test is performed
with a high power laser that can cover the entire detector
range using a beam splitter and lower power sensor that
has previously been tested for linearity for comparison.
Thus, in all cases, the linearity of the detectors is
traceable to NIST measurements.
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