35-3001-05-03 Carbon Dioxide Sample-Draw Detector • 11
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, monthly, 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 at the controller of the background concentration of CO
2
. Typical
background concentration of CO
2
is about 0.04% vol depending on location. Investigate
significant changes in the display reading.
Monthly Response Test
This procedure describes a test to verify that the sample-draw detector responds properly to the
target gas.
NOTE:
To reduce the response time of this test, use a short incoming sample line. If the sample-
draw detector’s sample line is long, connect a shorter line for this test. Make sure you
reconnect the sample line after you complete this procedure.
NOTE:
Performing a response test on the sample-draw detector may cause alarms. Be sure to put
the controller into its calibration program or disable external alarms before performing
this test.
Preparing for the response test
NOTE:
This procedure describes the RKI calibration kit that includes a demand flow regulator.
1. Verify that the controller display reading for the channel you are testing is consistent with
typical background levels of CO
2
.
If the display reading is not consistent with typical background levels of CO
2
, set the zero
reading of the transmitter as described in “Start Up” on page 10 of this manual, then continue
this procedure.
Performing the response test
1. Screw the demand flow regulator into the calibration cylinder.
2. Connect the calibration tubing from the demand flow regulator to the inlet fitting. Gas will
begin to flow.
