Teledyne 3010MA Operating Instructions Manual page 76

Part 2 Analysis Unit
The sample system delivers gases to the sensor from the gas inlet
located on the rear panel of the Analysis Unit. Note: There is no flow
limiting device inside the analysis unit and the flow rate must not
exceed 1000 SCCM. The Model 3010MA sample system is designed and
fabricated to ensure that the oxygen concentration of the gas is not altered
as it travels through the sample system. The sample encounters almost no
dead space. This minimizes residual gas pockets that can reduce response
time. The sample system is shown in Figure 6-6. This figure also shows
the user supplied components for selecting and delivering sample and
calibration gases to the Analysis Unit. If the auto calibration feature is to
be used, additional solenoid valves must be installed to allow automatic
sequencing of calibration and sample gases and tied in to the 50-pin
equipment interface connector as described in Part I Chapter 3 Section
3.3.2.3.
The rear panel of the Analysis Unit incorporates ¼ inch tube fittings
for sample inlet and outlet connections from the user's sample system. For
metric system installations, 6 mm adapters are available with each
instrument to be used if needed. The sample or calibration gas flowing
through the system is monitored by a flowmeter downstream from the
sensor. The gases delivered to the instrument should be at constant
pressure and have constant flow rates. They must exit freely to the
ambient atmosphere. The span, zero and sample gases should be delivered
at constant pressures of about 10 psig (Range 5-25 psig.) with standard
restictor. The flow rate must be maintained at about 500 cc/minute (range
300-1000 SCCM) and must exit freely to atmospheric pressure.
Referring to Figure 6-3, in the standard instrument, calibration gases
(zero and span) can be connected directly to the Sample In port by teeing
to the port with appropriate valves.
Prior to entering the instrument it is recommended that the sample
gas be passed through a 50 micron or finer filter. Calibration gases with
appropriate valves should be teed into the inlet line upstream of the filter.
A flow restrictor is supplied with the instrument and should be installed
between the filter and the gas inlet port. This limits the gas flow rate
through the paramagnetic cell. A flowmeter is installed on the exit side of
the cell which is visible on the Analysis Unit front panel (see Figure 6 -7)
The flowmeter is used to monitor the flow of gas through the sensor.
Readout is 0 to 1000 standard cubic centimeters per minute (SCCM).
Flow should be adjusted within the range 300-1000 SCCM, optimally
500 SCCM and should be stable. A 1/8 inch line is installed on the vent
Teledyne Analytical Instruments
Model 3010MA
76