Metrohm NIRS XDS Transmission OptiProbe Analyzer - Manual (Page 87)

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5
Instrument Fails Performance
Test.
1. Verify that the probes are positioned in the
calibration fixture, and that it is covered when the
test is initiated.
2. Temperature and/or humidity may be changing
rapidly during the test. This can usually be
observed as large spectral activity between 1300-
1400nm and 1800-1900nm. If this is the case, the
instrument should be tested in a more controlled
setting to verify proper operation.
3. Instrument may be located on a bench with
grinders, stirrers, or other laboratory equipment
which produces vibration or mechanical
disturbance. This shows up as spectral activity in
various areas, depending upon the transmitted
frequency of the motion. Turn off all equipment
that might cause such disturbance. Locate it to
another part of the laboratory, or place it on
isolated supports away from the XDS Analyzer.
4. Increasing noise in Performance Test may indicate
a gradually failing lamp. Performance Test is very
sensitive to any optical changes in the instrument,
including noise caused by lamp issues. Be sure the
instrument is warmed up, then run the test again.
If it continues to fail, consider a lamp change to
remedy the problem.
6
Instrument fails Instrument
Calibration.
1. Verify that the probes are positioned in the
calibration fixture, and that it is covered when the
test is initiated.
2. Verify that the Wavelength Standard is properly
positioned in the fixture when prompted by
software.
7
Instrument Gain is excessively
high in Gain Test.
1. NIR Gain should always be less than 100 on the
reference, unless extreme lengths of fiber are
used. If gain is high, verify that the probes are
positioned in the fixture and that nothing is
blocking the beam.
2. Verify that lamp is lit. (see above)