Understanding The Calibration Certificate; Photodetector Responsivity - ILX Lightwave FPM-8200 User Manual

Understanding the Calibration Certificate

Your FPM-8200 is supplied with a certificate for NIST traceable calibration from
ILX Lightwave's NVLAP
contains very useful information. The following discussion explains the meaning of
the information on your calibration certificate.

Photodetector Responsivity

The FPM-8200 Fiber Optic Meter is a stable low noise current meter with a
photodetector. Factory calibration is a process of recording detector current while
varying wavelength. The result is a table of detector responses every 10
nanometers, in mA per mW. When you connect input light, the FPM-8200
measures detector current, then uses the wavelength setting to look up the
conversion factor on the calibration table. Interpolation algorithms are used for
wavelengths between these calibration points. Note also:
• The highest detector current (greatest sensitivity) is at the longer wavelengths normally used
• Changes in detector response are significant enough that the meter must know the
• Detector response is less at shorter wavelengths.
01_10
for telecom work.
wavelength in order to properly display optical power.
FR O N T PA N E L O P E R A T I O N
Æ
certified NIST traceable laboratory. This certificate
Operating Guidelines
2
C H A P T E R
19
FPM-8200
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