Analytical Industries GPR-1000 ATEX Portable Trace PPM Oxygen Analyzer - Manual (Page 11)

11
Gas Connections:
The GPR-1000 flow through configuration is designed for positive pressure
samples and requires connections to incoming sample and vent female
quick disconnect fittings. The user is responsible for making provision for
introducing gases for calibration purposes.
Flow rates of 1-5 SCFH cause no appreciable change in the oxygen reading.
However, flow rates above 5 SCFH generate backpressure and erroneous
oxygen readings because the diameter of the integral tubing cannot
evacuate the sample gas at the higher flow rate.
A flow indicator with an integral metering valve upstream of the sensor is
recommended as a means of controlling the flow rate of the sample gas. A
flow rate of 2 SCFH or 1 liter per minute is recommended for optimum
performance.
Caution: Do not place your finger over the vent (it pressurizes the sensor)
to test the flow indicator when gas is flowing to the sensor. Removing your
finger (the restriction) generates a vacuum on the sensor and may damage
the sensor (voiding the sensor warranty).
To avoid generating a vacuum on the sensor (as described above) during
operation, always select and install the vent fitting first and remove the vent
fitting last.
Procedure:
1. Caution: Do not change the factory setting until instructed.
2. Designate the female quick disconnect fittings, right side of the analyzer, as inlet and vent respectively.
3. Regulate the pressure and flow as described in Pressure & Flow above.
4. Install one mating male vent fitting into the female quick disconnect fitting designated as the VENT –
connection of 1/8” dia. metal vent line (requires an 1/8” male NPT to tube adapter) is optional.
5. Connect the second mating male fitting to 1/8” dia. metal sample line using a 1/8” male NPT to tube adapter.
6. Connect the third mating male fitting to 1/8” dia. metal span gas line using a 1/8” male NPT to tube adapter.
7. Install either the sample or span mating male fitting into the female quick disconnect fitting designated as
SAMPLE.
8. Set the flow rate to 2 SCFH (open the flow control valve completely if using an external sampling pump
positioned downstream of the sensor).
9. Allow gas to flow through the analyzer for 3-5 minutes and proceed to Calibration or Sampling.
Power connection:
Locate a source of AC power to meet the area classification, plug in the appropriate charging adapter to the outlet
and connect the jack at the other end to the mating receptacle identified on the analyzer.