Cleaning the jet
Turn off the detector and its heated zone; also turn off gases to the detector
(particularly hydrogen). Allow time for the detector zone to cool.
1.
Remove the jet as described in the NPD detector chapter.
2.
Use a cleaning wire (0.016-inch od, 12-inch length, part no. 18765-20070)
to loosen/remove internal deposits.
3.
Wash both the internal bore and exterior of the jet with a 1:1 (V/V)
solution of methanol and acetone. The jet may also be cleaned in an
ultrasonic bath in the same solution.
Dry the jet with compressed clean air or nitrogen and heat in an oven at
70°C for at least 1/2-hour.
4.
Clean the detector base cavity using solvents, a swab or wire brush, and
low-pressure compressed air.
Jun 2001
Nitrogen Phosphorus Detector (NPD)
Cleaning the NPD jet and collector
Detectors
Agilent 6890 Gas Chromatograph Service Manual
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