YOKOGAWA CM6G, Руководство пользователя

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<8. Troubleshooting>
8-3
IM 11R02A01-02E 5th Edition : Dec. 28, 2016-00
2) Check any leakage in the pressure transmission pipe of each differential pressure
transmitter.
3) Check the temperature (thermistor resistance value) setting of orifice assembly.
→If the resistance value is not 3.6 to 4.2 kΩ, the temperature controller may have a failure.
8.4 Signal Section
Measure the output of each components by using digital voltmeter.
1) Set the “METER” switch on the front panel of the calorie detector to “P.MEAS” and
measure X5 of the computing station. If preheating is not required, the appropriate output
is approximately 0 to 20 mV, which is nearly proportional to 0 to (WI value, namely the
highest value in the measurement range). If preheating is required, the appropriate output is
approximately 4 to 20 mV, which is nearly proportional to 0 to (WI value, namely the highest
value in the measurement range).
For example:
When the WI value of the highest level in the measuring range is 100 WI, if the sample gas
is 80 WI, the voltage output is about 16 mV (when no preheating circuit).
→Although both the gas pressure control section and the differential pressure are normal,
the voltage output might be much varied. In this case there is a high chance that some
blockade exist in the air flow distribution line of the burner unit. Check the burner flame as
mentioned in paragraph 7.3.1.
→When the gas flame is coming out of the burner but the voltage output is very low , there
is a high chance that the wire is disconnected in thermocouple.
2) Measure 3 (+) and 4 (-) on the terminal board of the calorie detector. The normal voltage
output, when preheating circuit does not exist, is 1 to 5 V almost in proportion to 0 to (WI
value, namely the highest value in the measurement range). If preheating circuit exist,
approx. 1.8 to 5 V is almost in proportion to 0 to (WI value, namely the highest value in the
measurement range).
3) Measure 17 (+) and 18 (-) on the terminal block of the calorie detector. The appropriate
value is 23 V ±1%.
→It is due to a defect of the distributor in the calorie detector that the value is not normal.
4) Measure 15 (+) and 16 (-) on the terminal block of the calorie detector. The appropriate
value is 23 V ±1%.
→It is due to a defect of the distributor in the calorie detector that the value is not normal.
5) Measure 8 (+) and 7 (-) on the terminal block of the calorie detector. The appropriate value is
3 V ± 0.2 V.
→If the measured value varies much in spite of the air pressure control section being
normal, there is a high chance that the differential pressure transmitter has a defect.
6) Measure 6 (+) and 7 (-) on the terminal block of the calorie detector. The appropriate value is
3 V ± 0.2 V.
→ If the measurement value is greater than the appropriate value, even though the gas
pressure controller is normal, the differential pressure transmitter is considered to have a
defect.
7) When the density meter is attached, measure 3 (+) and 4 (-) of the density meter terminals.
Compare the gas density meter and the voltage output, then obtain an appropriate value ,
while reviewing the characteristics of gas density meters.
. →If the appropriate value is out of data in spite of no leakage, calibrate as according to the
paragraph 6.4.