Teledyne OT-2 operating instructions Sample Flow Description See Figure

2 Operational Theory Model OT-2 System

2.6Sample System

The system consists of a shut off valve, particulate filter, pres- sure regulator, scrubber, calibration selector valve, flow control valve, O2 transmitter and a sample flow meter and incorporates ¼ inch tube fittings for sample inlet and outlet connections at the side of the enclosure.

H2S from the sample gas can diffuse into the Micro-Fuel Cell leading to the formation of lead sulphide with the anode material. To eliminate the deleterious effect of H2S on the sensor, the scrub- ber is filled with Purafil®.

Sample Flow Description: (See Figure 2-4)

1.The sample enters the transmitter system via the shut off valve at 6-40 psig and passes through the filter where particulates, to 90 microns, are trapped.

2.A pressure regulator, which has been preset at the factory to approximately 5 psig ensures a constant gas flow to the sensor.

3.After the pressure regulator, the sample gas passes through the scrubber to the calibration selector valve.

4.When the sample has been selected, it flows through the flow control valve to the O2 sensor.

5.Finally, the sample flows through the flow meter and exits the system through the vent line to a safe area at atmospheric pressure.

Note: The flow control valve should be adjusted until the flow meter indicates a flow rate of 0.4 scfh.

		H2S	FLOWMETER
SAMPLE IN	FILTER	SCRUBBER	.1-1.0 SCFH
6-40 PSIG				VENT TO
			O2 XMTR	ATMOSPHERE
				PRESSURE
			0-10 PPM	(SAFE AREA)
			SPAN GAS IN

Figure 2-4 Flow Diagram

2-8 Teledyne Analytical Instruments