Analytical Industries GPR-35 Oxygen Analyzer - Manual (Page 17)

Advanced Instruments Inc.
17
Installing the Oxygen Sensor
GPR-35 Oxygen Analyzers are equipped with an integral oxygen sensor. They are fully
operational from the shipping container with the oxygen sensor installed, tested and
calibrated by the manufacturer prior to shipment.
Should it be necessary to install the oxygen sensor – see section 6 Maintenance which
covers replacing the oxygen sensor. Caution: All analyzers must be calibrated once the
installation has been completed and periodically thereafter as described below.
Caution: DO NOT open the oxygen sensor. The sensor contains a corrosive liquid
electrolyte that could be harmful if touched or ingested, refer to the Material Safety Data
Sheet in section 10. Avoid contact with any liquid or crystal type powder in or around the
sensor or sensor housing, as either could be a form of electrolyte. Leaking sensors should
be disposed of in accordance with local regulations.
Span Gas Preparation
Caution: Do not contaminate the span gas cylinder when connecting the regulator. Bleed the air filled regulator (faster and
more reliable than simply flowing the span gas) before attempting the initial calibration of the instrument.
Required components:
¾ Certified span gas cylinder with an oxygen concentration, balance nitrogen, approximating 80% of the full scale range
above the intended measuring range.
¾ Regulator to reduce pressure to between 5 and 30 psig, 30 psig recommended.
¾ Flow meter to set the flow between 1-5 SCFH, 2 SCFH recommended.
¾ 1 length of 1/8” dia. metal tubing measuring 4-6 ft. in length.
¾ 1 length of ¼” OD diameter Tygon or other plastic tubing, with a low permeability factor, measuring 4-6 ft. in length.
¾ Suitable fittings and 1/8” diameter metal tubing to connect the regulator to the flow meter inlet
¾ Suitable fitting and ¼” diameter plastic tubing to connect from the flow meter vent to the barbed fitting on the Calibration
Flow Adapter (P/N A-2344) or tube fitting designated SAMPLE IN.
Procedure:
1. With the span gas cylinder valve closed, install the regulator on the cylinder.
2. Open the regulator’s exit valve and partially open the pressure regulator’s control knob.
3. Open slightly the cylinder valve.
4. Loosen the nut connecting the regulator to the cylinder and bleed the pressure regulator.
5. Retighten the nut connecting the regulator to the cylinder
6. Adjust the regulator exit valve and slowly bleed the pressure regulator.
7. Open the cylinder valve completely.
8. Set the pressure between 5-30 psig using the pressure regulator’s control knob.
Caution: Do not exceed the recommended flow rate. Excessive flow rate could cause the backpressure on the sensor and may
result in erroneous readings and permanent damage to the sensor.