20 • 35-3001A-01-XX1 Sample-Draw Detector Operator’s Manual
Maintenance
This section describes maintenance procedures. It includes preventive maintenance
procedures. This section also includes procedures to troubleshoot the sample-draw detector,
replace components of the sample-draw detector, adjust the low flow setting, and remove the
particle filter’s tubing stub.
Preventive Maintenance
This section describes a preventive maintenance schedule to ensure the optimum performance
of the sample-draw detector. It includes daily and biannual procedures.
Daily Visual Checks
1. Verify that the Pilot LED is on.
2. Verify that the flowmeter indicates a flow rate of approximately 1.0 SCFH. If necessary
use the sensor flow control valve to adjust the flow rate to 1.0 SCFH. Turn the valve’s
knob counterclockwise to increase the flow and clockwise to decrease the flow.
3. Verify a display reading of 0% LEL 0% vol at the controller or a reading of 100 mV at the
amplifier test points. Investigate significant changes in the display reading.
Biannual Calibration
Calibrate the sample-draw detector as described in “Calibration” on page 26.
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended action for
problems you may encounter with the sample-draw detector.
NOTE:
This troubleshooting guide describes sample-draw detector problems only. See the
controller Operator’s Manual if the controller exhibits any problems.
Fail Condition
Symptoms
•
The sample-draw detector’s Fail LED is on.
•
The monitoring device is operating properly but indicates a reading well below zero or a
failure alarm.
Probable causes
•
The sample-draw detector’s flow rate is too low because of an obstructed sample line,
failed pump, etc.
•
The sample-draw detector is malfunctioning.
•
The sensor and/or amplifier wiring is disconnected or misconnected.
