Teledyne 311-D instruction manual Be Sure to Relock the Control After the ADJUST- Ment is Made

dictated by the customer’s application. If the instrument were being used to certify the oxygen content of a product for delivery, then a calibration prior to certification would certainly be in order. If, on the other hand, the instrument is being used to monitor or guard a sample, the evidence provided by the analyzer will determine when a calibration check is in order.

DO NOT CALIBRATE THE INSTRUMENT UNLESS THERE IS A TRACE OXYGEN GAS READILY AVAILABLE FOR PURGING IMMEDIATELY FOLLOWING THE CALIBRATION PROCEDURE. (The longer the instrument is exposed to high concentrations of oxygen, the longer it takes to get back to its working ppm range.)

3.2.1Calibration Procedure: Employ the following step-by-step procedure to calibrate the instrument:

1.Stand the instrument upright on a level surface, with the range switch in the “OFF” position.

2.Advance the range switch to the “CAL” position.

3.Install the plastic-tube-equipped male disconnect fitting in either of the analyzer’s sample ports, and a blank disconnect fitting in the other port (direction of sample flow is of no importance). A pump is recommended on the plastic tube. Pump the tube until the meter reading is stable.

CAUTION: DO NOT SUCK ON THE TUBE WITH YOUR MOUTH, THERE IS A

POSSIBILITY THE MICRO-FUEL CELL MAY LEAK. THE CELL CONTAINS KOH SOLUTION WHICH IS CAUSTIC AND EXTREMELY HAZARDOUS! (See Appendix - Material Safety Data Sheet).

4.Unlock and adjust the span control until the meter reads 20.9% oxygen.

BE SURE TO RELOCK THE CONTROL AFTER THE ADJUST- MENT IS MADE.

5.Immediately after Step 4 has been accomplished, disconnect the

tubing-

equipped calibration fitting, and plug in either the sample or a source of inert gas.

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If the instrument is to be used for sampling after the calibration procedure has been complete, follow the decreasing oxygen reading by positioning the range switch so that the meter gives the best possible resolution of the oxygen. DO NOT ATTEMPT TO ACTUALLY TAKE A READING UNTIL THE METER INDICATION STABILIZES. If the sample oxygen content lies within the limits of 0-100 ppm, an overnight purge is recommended for the instrument to recover sufficiently from the effects of the 209,000 ppm oxygen concentration of air (over four decades of range differential). Recovery time is proportionally less for coarser ranges.