Frequently Asked Questions

A:  The key commissioning issue is to regulate the sample and cal gas inlet pressures to below 6 psig.​

A:  Both zero and span regulators should be purged at least a few times. I think the manual states to purge each line for 8-12 hours, but I've purged for under three hours with no issue if everything else was done correctly. I typically purge span line, then zero, then power unit on zero gas. 

If this does not solve the problem, they will need a voltmeter and potentiometer adjustment tool and will need to access the back of the unit to adjust a couple PCB pots. This may be required from time to time. ​

A:  The procedure is as follows: 

1. Perform the calibration procedure per Section 4.2 of Teledyne’s Model 2120 Manual. It is important the Test Point voltage (from the terminal on the rear of the unit) be set to 126 mVDC as discussed in Section 4.2.3 #4. 

2. If the analyzer reads correctly on zero gas but reads over-range and triggers the Over range alarm, perform the Setting the Over range procedure below. 

Setting the Over range​ 

3. Apply zero gas. 

4. On the rear of the unit, remove the plate covering the right portion by removing the screws. On the PCB on the left side, place a voltmeter on the red and black test points and adjust the GAIN potentiometer until red and black test points read 4.75 VDC. 

5. Apply span gas. 

6A. If the span gas concentration is that of the full-scale operating range (e.g. the analyzer range is 0-200ppm N2 in Argon and the gas is 200ppm N2 in Argon), set the THRESHOLD potentiometer until alarm LED is at the threshold of illumination. Both the light behind back panel and alarm light will be illuminated. 

6B. If the span gas is less than the full-scale operating range (e.g. the analyzer range is 0-200ppm N2 in Argon and the gas is 180ppm N2 in Argon), set the THRESHOLD potentiometer until alarm LED is NOT illuminated If the concentration is fairly close to the range, adjust the potentiometer approximately half to one turn past the point of the LED not being illuminated. ​

A:  Here is the procedure for setting the over range circuit. He can perform the whole procedure or just adjust the THRESHOLD pot until the over range goes out. 

DO NOT TOUCH ANY OTHER POTS. Be sure your are adjusting the correct pot. 

1.Run on zero gas. Open the back panel and set the photo diode GAIN pot to 4.5 to 5.0VDC using the test points on the board. 

2.Run the over range gas and set the THRESHOLD pot until alarm just LED ILLUMINATES. Light behind back panel and alarm light on front should illuminate simultaneously. 

3.Low flow will produce an over range light. ​