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Appendix 1: DPG4000 Calibration Procedure
Overview
Calibration adjustment of the DPG4000 is performed electronically via
internal software with the case closed. There are no mechanical
adjustments; all calibration commands and adjustments are done via
the keypad, using the display to guide the user through the calibration
process.
Eight calibration points are used in the adjustment program, working
from full scale to zero at pressures equaling 100%, 87.5%, 75%, 62.5%,
50%, 37.5%, 25%, 12.5%, and 0% of full scale plus vacuum.
Note
: This is an ambient temperature calibration, and should be
performed at an ambient temperature of 23° C ± 3° C (72° F ± 5° F).
Calibration outside this temperature range will invalidate the
temperature compensation program in the DPG4000.
Calibration Interval
You should check performance of the DPG4000 at the interval
required by your calibration program. We recommend adjustment
when measurement deviates by more than 75% of the specified
accuracy, or 0.04%
Test Equipment
Verification and calibration of the DPG4000 requires pressure and/or
vacuum standards able to produce and indicate pressures from
vacuum to the full-scale range of the unit under test. In order to
maintain the specified accuracy of the DPG4000, standards should
have a TUR of 4:1 or better.
Connections:
The DPG4000 uses a 1/4 NPT male connection in the pressure input
port. Various adapters may or may not be needed to connect to the
pressure standard. Always make sure the hose, tubing, and fittings etc
have a rated working pressure at or above the pressure of the unit.
Also it is important that there be no leaks when performing calibration;
use Teflon tape where appropriate.
Entering Calibration Mode:
After you have made your connections, turn the power on while
holding the CONFIG key. Use the arrow keys to enter the password.
The password is 101. If you have entered calibration mode correctly
the display should look as shown below. The pressure value displayed
will be the full-scale value of the gauge.
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