Chapter 7 Troubleshooting
GC-2014 Service Manual
104
7.1.1.4 Precautions for Flow-Rate Control Settings (DetAPC)
(1) The pressure or flow rate fluctuates.
Check that I time = 10, P term = 50, and I term = 20.
If the values are different from the above values, input these values and
press the pf4 key to write them in the ROM.
Check that the source pressure is not fluctuating.
If the source pressure is shared (e.g., the helium carrier gas is used for the
detector's make-up gas and carrier gas), check for pressure fluctuations in
the other line.
(2) The pressure or flow rate is lower than the setting.
Check for leaks in the line.
Check that the source pressure (i.e., the primary pressure) has attained a
sufficient level.
Check that I time = 10, P term = 50, and I term = 20.
If the values are different from the above values, input these values and
press the pf4 key to write them in the ROM.
Check the offset and gain values for the pressure.
The offset value is normally in the range 32,000 to 33,500 and the gain
value is normally in the range 3,000 to 10,000. If the offset value is well
outside this range, perform offset calibration. (The method is described in
the GC-2014 instruction manual.) If the gain value is well outside this range,
obtain the correct value from Shimadzu Corporation's Quality Assurance
Department. At this time, provide notification of the serial number and lot
number displayed on the side of the AFC.
Check the settings to confirm that, for example, APC is not "off" and that the
ignition operation has not been forgotten.
If 0 is displayed as the valve voltage, this indicates that there is no voltage
being supplied from the control system to the valve that is attempting to
supply gas.
(3) The pressure or the linear velocity is higher than the setting.
Check that I time = 1, P term = 50, and I term = 20.
If the values are different from the above values, input these values and
press the pf4 key to write them in the ROM.
Check the offset and gain values for the pressure.
The offset value is normally in the range 32,000 to 33,500 and the gain
value is normally in the range 3,000 to 10,000. If the offset value is well
outside this range, perform offset calibration. (The method is described in
the GC-2014 instruction manual.) If the gain value is well outside this range,
obtain the correct value from Shimadzu Corporation's Quality Assurance
Department. At this time, provide notification of the serial number and lot
number displayed on the side of the AFC.
To Next Page
Loading...
