Metek 920, Operator'S Manual With Essential Health And Safety Requirements

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4-66 | Model 920 Multi-Gas Analyzer
Analog Output Calibration
Calibration of an analog output is performed by entering the measured
zero- and full-scale signals for the current output channel. Enter these val-
ues in decimal form. Use a current meter to calibrate the current output
signals. These values are used to offset the output to the correct values.
If the measured current output is less than 20 mA when the output
is set to full-scale, it cannot be increased above that value. The V/I
module must be replaced if this value is unacceptable. The output
channels have been calibrated at the factory and will be re-calibrated
upon initial installation at the site. Further re-calibration is required
only when a V/I module or the
Termination board is replaced.
Pressing Esc at any time during the procedure will abort the proce-
dure and return to CAL mode normal display. The existing calibra-
tion values and any new values entered up to the point of pressing
Esc will be retained.
To calibrate the current output signal for Output Channel ‘ z ’, where ‘ z ’ is
the output channel number ( 1..4 ), connect the current meter to the output
(see Figure 4-8 for termination points) and press:
Zero current output F6 0 z Current output zero-scale value is displayed, where
‘ z ’ is the Zero current output ( IZero ) 1..4.
Del Sets the current analog output channel to zero-scale
(4 mA).
nnn Enter the zero-scale value (mA) that was measured by
the meter.
Ent Zero-scale value is entered and displayed.
Span current output F6 1z Current output full-scale value displayed, where ‘ z ’ is
the Span current output ( ISpan ) 1..4.
Del Sets the current analog output channel to full-scale
(20 mA).
nnn Enter the full-scale value (mA) that was measured by
the meter.
Ent Full-scale value is entered and displayed.
Calibration complete Ent To return to CAL mode normal display, or
Esc To return to RUN mode normal display, or
Enter another command to perform another function.

NOTE
!
CAUTION