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9 CALIBRATION (CAL) MODE
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9.3.1 Connecting a Pressure Calibrator
This section provides the procedure of the DPS span inspection using the Pressure Calibrator.
<Operation>
1) Turn on the power of the Pressure Calibrator about 10 minutes before calibration for a warm-up.
2) Unplug the sealing plugs from both the WORK CAL. PORT and the MS PORT-side LEAK CAL. ports on
the front panel of the tester.
(The LEAK CAL port is M10 ×1.5. A fitting, M10-Rc/1/4, is available upon request.)
3) Disconnect the pressure source and make sure that the air is exhausted completely from the pneumatic
circuit of the tester. Leave the pilot pressure source as it is.
4) Close the both the WORK and the MASTER-side stop valves.
5) Connect WORK port of the pressure calibrator to WORK CAL. PORT, and MASTER port of the
pressure calibrator to MS PORT.
6) While
oFS
is displayed on the leak rate indicator, pressing the START key switches the display to
SPn
.
Valves are actuated and the BAL stage is followed by the DET stage, with the output of the DPS being
displayed at the completion of auto-zeroing.
7) Close the shutoff valve of the pressure calibrator and generate a pressure (±100 Pa, ±950 Pa) by
turning the knob of the pressure calibrator. Verify if the reading of the tester and that of the pressure
calibrator are the same.
8) Press the STOP key to enter an atmospheric state. Press again to return to Measurement mode.
9.3.2 Changing gain coefficients
1) If there is only a slight difference between a reading and the reference value, the DPS span can be
adjusted with the key operation. Displayed DPS readings are multiplied by a gain coefficient in all
modes. Range of the Gain coefficients is between 0.9 and 1.1.
Reading = DPS × Gain coefficient
2) While a span is displayed during the DET stage, the gain coefficient can be changed. Introduce
differential pressure of +950 Pa to the tester with Pressure calibrator, and press
▲
UP or DOWN
▼
key
to equalize the displayed values of the tester and Pressure calibrator during the DET stage. Repeat
the same procedure for -950 Pa.
3) If the gain coefficient is changed, the reading blinks. Pressing the ENTER key stores the gain
coefficient in the memory. Pressing the STOP key cancels the change.
4) Verify the gain coefficient.
The gain coefficient can be viewed by pressing the
◄
LEFT and RIGHT
►
keys simultaneously for 1
second or longer.
Be sure to let the air in the tester exhaust completely, or the
calibrator may be damaged because of over pressurization.
CAUTION
DPS span calibration is performed by the Cosmo’s representatives.
One’s who has been specially trained by Cosmo could also perform it. In
such case Cosmo does not guarantee the value after the calibration.
CAUTION
DPS calibration is required if the reading of the DPS output
gets out of the allowable range.
NOTE