WIKA CPC6000 - Manual (Page 89)

Automated Pressure Calibrator
CPC 6000
Mensor/WIKA Operating Instructions - CPC 6000 89
10. Calibration
10.1 General
The CPC 6000 automatically adjusts the pressure reading for the effects of temperature and non-lin-
earity within the calibrated temperature range of 15-45°C. The process is referred to as dynamic com-
pensation because each reading is so adjusted before it is output to the display or to a communication
bus. Thus, a calibrated CPC 6000 operated within its temperature band, and with proper zero and
span adjustments, will provide accurate pressure measurements.
10.2 Environment
For maximum accuracy, allow the CPC 6000 to warm up for a minimum of 15 minutes in an ambient
temperature within the compensated range prior to commencing a calibration. In addition the instru-
ment should be at rest on a stable platform that is free of excessive vibration and shock.
10.3 Pressure Standards
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/IEC 17025:2005, or other applicable standards.
10.4 Media
The recommended calibration medium is dry nitrogen or clean dry instrument air. A height variation
between the standard and the CPC 6000 can cause significant errors. See “
10.9 - Head Pressure Cor-
rection” for further information.
10.5 Calibration Setup
Figure 10.5 - Calibration Setup illustrates a typical setup for either local or remote calibration for an
absolute or gauge pressure instrument. In the illustration the ‘Optional Computer’ is required only for
performing a remote calibration.
The ‘Pressure Standard’ is normally a deadweight test instrument, and the ‘Volume Controller’ refers to
a hand operated variable-volume pressure vernier device. A diaphragm type vacuum gauge is recom-
mended over the gauge tube type of vacuum sensor for calibrating sub-atmospheric pressures (see
Figure 10.5 under “Setup for Absolute Pressure”). A vacuum source with a capacity of generating 600
millitorr is recommended.