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Typical sample gas flow problems – Teledyne GFC-7000E - Trace CO2 Analyzer User Manual

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Model GFC7000E Instruction Manual

TROUBLESHOOTING & REPAIR PROCEDURES

04584 Rev A1

193

independent flow meter to perform a flow check as described in Section 9.3.4. If this test shows
the flow to be correct, check the pressure sensors as described in Section 11.4.6.5.

11.1.6. Typical Sample Gas Flow Problems

11.1.6.1. Flow is Zero

The unit displays a SAMPLE FLOW warning message on the front panel display or the SAMPLE
FLOW
test function reports a zero or very low flow rate.

Confirm that the sample pump is operating (turning). If not, use an AC voltmeter to make sure
that power is being supplied to the pump. If no power is present at the electrical leads of the

pump.

1. If AC power is being supplied to the pump, but it is not turning, replace the pump.

2. If the pump is operating but the unit reports no gas flow, perform a flow check as described in

Section 9.3.4.

3. If no independent flow meter is available:

• Disconnect the gas lines from both the sample inlet and the exhaust outlet on the rear

panel of the instrument.

• Make sure that the unit is in basic SAMPLE Mode.

• Place a finger over an Exhaust outlet on the rear panel of the instrument.

• If gas is flowing through the analyzer, you will feel pulses of air being expelled from the

Exhaust outlet.

4. If gas flows through the instrument when it is disconnected from its sources of zero air, span

gas or sample gas, the flow problem is most likely not internal to the analyzer. Check to make
sure that:

• All calibrators/generators are turned on and working correctly.

• Gas bottles are not empty or low.

• Valves, regulators, and gas lines are not clogged or dirty.

11.1.6.2. Low Flow

1. Check if the pump diaphragm is in good condition. If not, rebuild the pump (see Section

9.3.2). Check the Spare Parts List for information of pump rebuild kits.

2. Check for leaks as described in Section 9.3.3. Repair the leaking fitting, line or valve and re-

check.

3. Check for the sample filter and the orifice filter for dirt. Replace filters (see Sections 9.3.1 and

11.5.1 respectively).

4. Check for partially plugged pneumatic lines, orifices, or valves. Clean or replace them.