Chauvin Arnoux C.A 852 Notice De Fonctionnement page 12

4. OPERATION OF THE INSTRUMENT
4.1. «MONITORING» MODE
When you press the «REC» button, you access the «monitoring» mode.
Before going into this mode, select the unit of pressure, as you will not be able to change it once you
are in monitoring mode.
When you press the button, a clock is started and "REC" is displayed on the screen.
This mode enables you to time/date-stamp the maximum and minimum values in your measuring operation.
When you press the "REC" button a second time, MAX is displayed on the screen and the maximum
value from the measuring operation is indicated on the main screen. The clock indicates the time when
this event occurred during the measuring operation.
When you press a third time, you obtain the same information for the minimum value.
A fourth press returns you to the current value.
To exit from this mode, press the "REC" button for 3 seconds.
Note: The "differential measurement" mode is not accessible from the "monitoring" mode.
4.2. «DIFFERENTIAL MEASUREMENT» MODE
When you press the «DIF» button, you access the «differential measurement» mode.
The differential measurement mode measures the difference between two pressures. But it can also be
used to quantify pressure variations (connect one input to your system and leave the other at atmospheric
pressure).
Before going into this mode, select the unit of pressure, as you will not be able to change it once you
are in monitoring mode.
When you press the button, the "DIF" symbol and the relative zero are displayed on the screen. From
now on, only the pressure change will be indicated.
To exit from this mode, press the "DIF" button.
4.3. ADJUSTMENT OF THE ZERO
Leave the inputs at atmospheric pressure and press the «HOLD» button for 2 seconds. The screen
switches off, indicates «0.0.0.0» from right to left and then the zero is displayed.
4.4. CALIBRATION AD ADJUSTMENT OF THE INSTRUMENT
Calibration can only be performed using a pressure calibrator.
„ First, set the zero
„ Then switch off the instrument
„ Press the "REC" and "power" buttons simultaneously. "CA" appears on the screen. You are now in
setting mode.
„ Check that the unit selected is "psi" before starting to adjust the positive input.
„ By default, the CA 852 uses 1.6 psi as the calibration point. However, it can be set between 1.5 and
1.7 psi. If the calibration source is not at 1.6 psi, adjust the calibration point with the "DIF" button to
increase and with the "back-lighting" button to reduce.
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