WIKA CPG2300 Series, Руководство по эксплуатации

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Operating Instructions CPG2300 Series 41
Portable Digital Pressure Gauge
CPG2300 Series
9.3 Pressure Standard
Mensor recommends the use of appropriately accurate primary pressure standards
when calibrating this instrument. Such standards should be sufficient so that when the
techniques of the ISO Guide to the Expression of Uncertainty in Measurement (GUM)
are applied, the instrument meets its accuracy statements as required by ISO 17025, or
other applicable standards. The same requirement applies to the vacuum gauge used to
set the zero offset on absolute calibrations. The recommended absolute pressure level
for setting the zero offset is
≥
300 millitorr.
9.4 Calibration Medium
The recommended calibration medium for sensors up to 2500 psi is dry nitrogen. Hy-
draulic media (water or oil for example) are recommended for ranges above 2500 psi.
Hydraulic media can be used with some lower ranges. However, special techniques
must be used in filling the connection lines and transducer.
9.5 Calibration Process
The calibration process described below is for local operation via the instrument key-
pad. Connect the CPG2300 sensor to be calibrated as shown in Figure 9.2.
When the Calibration function is selected from the sensor setup screen, the password
entry screen will be displayed. Enter the four-digit password and then press the
♦
(enter) key. For more information on entering or changing the password, see the Local
Operation section.
9.5.1 Zero Adjustment
Access the zero calibration screen as described in the Local Operation section.
For a gauge sensor: Vent the CPG2300 and adjust the display to show zero pressure
by using the arrow keys on the front panel. When zero is shown, press the
♦
(enter) key.
For an absolute sensor: Connect a vacuum source to the pressure port of the sensor
to be calibrated. Evacuate the sensor to a low pressure that will still maintain a viscous
flow, typically 300 millitorr, or greater. (At pressures lower than 300 mTorr, the actual
pressure at any particular point in the system is questionable.) Allow sufficient time for
the applied pressure to stabilize and adjust the measured pressure on the zero calibra-
tion screen to match the true applied pressure. Press the
♦
(enter) key to store the zero
offset.
For a bi-directional sensor: Apply a negative pressure source equal to R-.