Ametek Dycor CG1000-RTP, Руководство пользователя

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6-6 | Dycor CG1000-RTP Oxygen Analyzer
Reversed Thermocouple
Wires
To check if the thermocouple wires
are reversed, use the controller to
display the thermocouple millivolts
so that they appear on the front
panel display.
If the millivolts are negative, the
thermocouple wires are reversed.
Thermocouple Compensation Circuit Check
Use a volt meter to measure across capacitor C3 on the back-
plane board. If you measure 15 volts at capacitor C3, measure
across connections labeled TC- and Cell- on the backplane
board. Twelve (12) millivolts should be measured. This signal
is a function of ambient temperature and may be up to
± 2
milli-
volts at extreme ambient temperatures.
If you don’t measure this voltage, replace the backplane board
Wiring Checks
Make sure all wiring connections are terminated to the
proper locations and are seated properly. Ensure wires are
not reversed and the cable is not damaged.
Backplane Board
Connection
Connector Label Wire Connection
TB2 - Pin 1
TB2 - Pin 2
cell +
cell -
cell lead
no connection
TB2 - Pin 3
TB2 - Pin 4
Tc +
Tc -
T/c Yellow lead
T/c Red lead
TB1 - Pin 1
TB1 - Pin 2
Furnace
Furnace
Furnace lead
Furnace lead
(no polarity)
Calibration Checks
Calibration Setup Checks
Check that the correct calibration
gas values have been entered into
the control unit.
- Select the Cal Gas Value menu
option from the Calibrate Key on
the control unit and check that the
calibration gas values entered match
the analyzed concentration of the
cylinders.
Calibration Gas Check
Are the calibration gas cylinders turned on? Are they empty?
Does the calibration gas bottle pressure have at least 500 lb.
of pressure?
Are the flow rate and delivery pressure of calibration gases
correct. Calibration gas flow rates should match the flow
rates used for normal operations.
Calibration Line Check
Ensure that your calibration line is
not contaminated with such things
as pipe dope, cutting fluid, oil or
solvents. All these contaminants
produce hydrocarbon vapors that
interfere with the proper calibration
of your analyzer leading to lower-
than-expected oxygen readings.
To test for contaminated lines, you must temporarily bypass
your current calibration line with a clean calibration line
(directly from the calibration gas cylinder to the sensor calibra-
tion inlet port using a flow meter to set the proper flow) and
compare the response with that from the possibly contaminat-
ed line. The best calibration gas to use for this check is O
2
zero
calibration gas.