Analytical Industries GPR-1500 A Series Trace PPM Oxygen Analyzer - Manual (Page 16)

Advanced Instruments, Inc
16
Gas Connections
The GPR-1500-A with its standard flow through sensor housing configuration is designed for positive
pressure samples and requires connections for incoming sample and outgoing vent lines. The user should
adhere to the recommendation in terms of using the type of fittings, tubing, sample/span/zero gas pressure
and sample flow rates. Failure to do so may cause permanent damage to the sensor.
Procedure:
Caution: Do not change the factory setting until instructed to do in this manual.
1. If analyzer has no marking for sample inlet and sample vent, designate one of the bulkhead tube fittings
as the VENT and the other as SAMPLE.
2. Regulate the sample pressure as described in “Pressure and Flow” section above.
3. Connect a 1/8” or a ¼” vent line to the compression fitting to be used for venting the sample.
4. Connect a 1/8” or ¼” sample line to the compression fitting to be used to bring SAMPLE gas to the
analyzer.
5. If equipped with optional SPAN and/or ZERO ports, connect the SPAN and the ZERO gas lines to the
respective SPAN and ZERO ports of the analyzer
6. Set the SAMPLE, SPAN and the ZERO gas pressure between 5-30 psig..
7. Select sample gas and allow it to flow through the transmitters and set the flow rate to1- 2 SCFH.
Flow rates of 1-5 SCFH cause no appreciable change in the oxygen reading. However, flow rates above 5
SCFH may generate a backpressure and cause erroneous oxygen readings due to fact that the smaller
diameter of the integral sample system tubing cannot vent the sample gas quickly at higher flow rates. If the
analyzer is not equipped with an integral flow control valve, a flow control metering valve with a flow
indicator upstream of the sensor must be installed to control the flow rate of the sample gas. A flow rate of 1-
2 SCFH or 0.5-1 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
sudden vacuum on the sensor and may lead to electrolyte leakage thus causing damage to the
sensor (will void sensor warranty).
Electrical Connections
Incoming power and signal output connections are made to terminal blocks mounted on a PCB located in
the metal enclosure and accessible from the rear of the enclosure.
Do not supply voltage more than specified in this manual and noted near the power input
terminal of the transmitter.
Install all power, alarm relay and signal output connections in accordance with recognized
electrical standards. Supply power to the terminal marked “POWER”. Do not exceed the
recommended power rating.
Ensure the positive and negative terminals of the power supply are connected to the appropriate
terminals of the terminal block as marked.
Avoid electrostatic discharge - Clean all surfaces with a damp cloth only.