Oldham TCOD-IR Operating Instructions Manual page 10

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Zero-Point Adjustment at Output Signal = 4 mA (Potentiometer Z (Zero)).
(The sensor is subjected to zero gas with a volume flow of 0,5l/min.).
Using an ameter (set to mA DC), the voltage is measured across the signal path of the "mA"
terminal (positive) , note, - the cable must be disconnected from this terminal.
Output voltage is set to 4 mA with potentiometer Z, clockwise turning of which increases the
output voltage.
•
Span Adjustment at Output Signal (Potentiometer S (Span)).
The sensor is subjected to standard test gas with the aid of a calibration adapter (above 2nd
alarm level or in upper third of measuring range).
Output voltage in compliance with the calibration curve is set with potentiometer S, clockwise
rotation of which increases the output voltage.
Should the amplification not be enough if the potentiometer has been turned fully clockwise as
far as possible, the jumper J2 should be relocated into the upper position and the adjustment
repeated.
•
Verification of Zero-Point and Span Calibration
Zero-point adjustment for 4 mA is once again repeated and checked. Should further adjustment
become necessary, span adjustment again needs to be repeated. Subsequent checking must
be repeated until deviations at 4 mA or with standard test gas are below approx. ± 0.1 mA.
mA
Z
+
X1
S
J2
10
mA
4..20 mA
Ground/Masse
24 VDC