Teledyne Reference Gas Flow, Zero Gas Flow, Warmup, Zero Standardization, Model 212R

Thermal Conductivity Analyzer Model 212R

4.Determine what the sample pressure is and set the output pressure of the cylinder gas supplies to agree with the sample pressure. This procedure, although not absolutely necessary, will minimize flow adjustments when the sample path is switched to the various inputs.

5.Turn the analyzer and recorder power switches to “ON”.

3.2Reference Gas Flow.

Open the reference gas throttle valve adjacent to the “Ref. Flow” meter, and set the valve for an indicated flowrate of between 0.1 and 0.3 scfh. Since the actual setting is not critical, TAI suggests that the flow be set at 0.1 scfh to conserve the reference gas supply.

3.3Zero Gas Flow.

Open the “ZERO” valve (ccw until a release in tension is felt), and adjust the throttle valve to the right of the “SAMPLE FLOW’ flowmeter for an indi- cated flowrate of 0.3 scfh.

3.4Warmup.

A warm-up period of twenty-four (24) hours is recommended to stabilize theinterioroftheanalyzeratthecontroltemperaturelevel. Untilthemeasuring celltemperaturehasequilibratedwiththecontroltemperature,theoutputsignal willdrift.

During the warmup period, check the recorder periodically. As the drift rate decreases, increase the sensitivity by moving the range switch towards Range #1.

IMPORTANT:

The zero control will have little or no effect until Range #1 is reached. If the recorder is off scale towards electrical zero (negative signal) after 24 hours of running on zero gas, use the procedure outlined in Section 6.2. The drift rate will decrease exponentially. When the rate of change slows to approximately 1% per hour, place the “RANGE” switch on position #1 and readjust the “ZERO” control so that the recorder is reading midscale. Do not attempt to calibrate the analyzeruntiltherecorderindicationstabilizes.

3.5Zero Standardization.

Teledyne Analytical Instruments 13