Apollo IMY instruction manual Analog Output Calibration, To 20 mA Calibration

ANALOG OUTPUT CALIBRATION

Although the analog output has been calibrated at the factory, zero and span adjustments are provided to compensate for small offsets and drifts. If excessive drift is noticed, the following calibration procedure may be performed.

Scale the analog output by entering an arbitrarily larger display value for “AN-HI”then for “AN-LO”, in “PRO 8”.

Note: Set the analog output source assignment for input.

4 to 20 mA Calibration

Exit the programming mode and apply a (temperature)/(resistance) to the input of the indicator so that the display reading is below that of the value entered for “AN-LO”. Adjust the zero potentiometer (right side) so that exactly 4.00 mA flows, as verified by an accurate ammeter. Next, apply a (temperature)/ (resistance) to the indicator so that the display reading is above that of the value entered for “AN-HI”. (See Appendix “B” for max. input voltage.) Adjust the span potentiometer (left side) so that 20.00 mA is flowing. Repeat the zero and span adjustments until both are accurate. Analog output calibration is complete.

0 to 10 VDC Calibration

Exit the programming mode and apply a (temperature)/(resistance) to the input of the indicator so that the display reading is below that of the value entered for “AN-LO”. Adjust the zero potentiometer (right side) so that exactly

0.00VDC flows, as verified by an accurate voltmeter. Next, apply a (temperature)/ (resistance) to the input of the indicator so that the display reading is above that of the value entered for “AN-HI”. (See Appendix “B” for max. input voltage.) Adjust the span potentiometer (left side) so that 10.00 VDC is flowing. Repeat the zero and span adjustments until both are accurate. Analog output calibration is complete.

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