Teledyne 4060 manual Measuring Circuit Electrical Checks, Maintenance Series, Anode Voltage Check

Maintenance Series 4060

attempt to evaluate performance on sample gas. If analyzer sensitivity is questionable, use the span gas. For all other evaluations, use the zero gas and low range for maximum sensitivity. The important consideration is to control as many variables as possible. Using cylinder-supplied gases of known hydrocarbon content eliminates the possibility of introducing an unknown variable.

Do not overlook the seemingly obvious. Check to see that power is available for the instrument (and of the proper voltage, etc.), and that connections are correct. Also verify that support/calibration gases are not depleted.

5.1 Measuring Circuit Electrical Checks

If the analyzer performs erratically on span gas, the trouble can be related to either the integral gas control systems, or the electronics. To isolate the problem, the two systems must be separated. To isolate the electronics, employ the following procedure:

Open the door to the analyzer, remove and disconnect the collector cable from the sensor leaving it attached to the electrometer board. (Consult schematic and assembly drawings for circuitry and location). With this cable disconnected, the electronic circuitry is completely isolated from the gas control system and cell.

5.1.1Anode Voltage Check

If the output can be adjusted by the zero control (the above section, step 2), the cell anode voltage should be verified as follows:

WARNING: THESE PROCEDURES SHOULD BE CARIED OUT ONLY BY PERSONNEL FAMILIAR WITH HIGH VOLTAGE CIRCUIT BOARDS. THE ANODE-IGNITER UNIT AND ASSOCIATE CIRCUITRY INVOLVE DANGEROUSLY HIGH VOLTAGES.

Refer to the cell wiring diagram. Using a voltmeter set to measure

125 VDC, check the voltage on either of the anode-igniter electrodes, as follows:

1.Connect the negative voltmeter lead to ground and the positive lead to either electrode. Be careful not to short the circuit by touching both an electrode and the cell body simultaneously. The reading obtained should be 125±10 VDC.

66 Teledyne Analytical Instruments