Low Flow Switch; Control Relay - Teledyne 2120 Operating Instructions Manual

Maintenance
filter is installed, mirror-side out, from inside the PMT cover
when it is removed from the PMT.
3. Wipe the filter clean with a damp, lint-free cloth. Use only
water. Do NOT use detergent.
4. Replace the filter into the window opening with the mirror-side
out.
5. Replace the cover on the PMT. Take care to keep the filter and
window lined up with the vertical grid visible within the tube. If
this is done correctly, the window and filter face the analytical
cell when the PMT is keyed into its socket.

5.4.3 Low Flow Switch

To test the flow switch operation:
1. With the analyzer running, slowly decrease sample flow. As the
flow falls below approximately 75 ccpm, the Low Flow Switch
should activate the relay to cut off the ionizing voltage from the
transformer. When this happens, the front panel LOW FLOW
light turns on, and the IONIZER light turns off. The
OVERRANGE ALARM condition is also activated.
2. Slowly increase the sample flow up toward the 2 scfh analyzer
flow rate. As the flow increases above approximately 100
ccpm, the switch should activate the control relay to apply
ionizing voltage to the analytical cell. When this happens:
•
The control relay switch activates.
•
The front panel LOW FLOW light turns off.
•
The IONIZER light turns on.
3. If the events listed in steps 1 and 2 do not take place, either the
low flow switch or the control relay is not functioning properly.
Test the control relay to isolate the problem.

5.4.4 Control Relay

To test the relay:
1. Remove the AC power cord from the unit.
Teledyne Analytical Instruments
44
Model 2120