WIKA CPC6000 - Manual (Page 93)

Automated Pressure Calibrator
CPC 6000
Mensor/WIKA Operating Instructions - CPC 6000 93
7. When satisfied that the new password is correct, and a written copy has been stored, press [OK]
to complete the entry. The previous password is immediately replaced by the new one.
8. Confirm that the new password is valid by pressing [Main], then repeat steps 1 through 3 to return
to the Calibration Data screen (Figure 10.6.1C). If this screen can’t be accessed using either the old
or the new password contact Mensor.
10.7 Restoring a Mensor Calibration
The offset and slope values established for each turndown at the final factory calibration are stored in
permanent memory within each transducer. These factory values can be restored at any time regard-
less of the number of subsequent calibrations. To restore the factory calibration to the active turn-
down, press [Restore Factory Cal] on the unlocked Data Entry screen seen in Figure 10.6.1C. This will
restore both the factory zero offset and slope calibration values to the active turndown. The [Restore
Factory Cal] function can be repeated for each turndown as desired.
10.8 On-site Calibration
The CPC 6000 can contain one primary transducer and barometric reference and may have an addi-
tional, secondary transducer. Each transducer (except the Barometric Reference Transducer) can have
up to two separately calibrated ranges (two turndowns). Zero and span adjustments are available for
each of these turndowns.
Linearity is preset at the factory and is not adjustable. One and two point calibrations are used to
make a linear correction to the pressure readings using the formula: (uncorrected reading) X slope) +
offset. The one point calibration adjusts the offset, the two point calibration adjusts both the offset and
the slope.
10.8.1 CPC 6000 Preparation Procedure
The following is a step-by step instruction for calibrating a selected turndown.
Evacuate the pressure transducer(s) to a low pressure that will still maintain a viscous flow, typically
600 millitorr (0.0116 psi). At pressures lower than this the pressure at any particular point in the sys-
tem is questionable. Allow from five to ten minutes for the target pressure to stabilize, then convert the
millitorr reading to an equivalent instrument reading in the active measurement units. Table 11.3 in the
Appendix Section lists millitorr conversion factors.
To begin a calibration, press the [Calibrate] tab and unlock the calibration screen as described in the
previous section. Select the turndown to calibrate from the drop list and the units in which to perform
the calibration on the unlocked calibration data screen.
10.8.2 [Calibrate] Setup Key
The Calibration screen shown in Figure 10.8.2A is the first of several screens relating to the calibration
functions. This screen allows the user to perform any of the following tasks:
1. Calibrate zero and span values on any turndown open of all installed sensors. An Absolute CPC
6000 allows calibration of the barometric reference transducer;
2. Establish a new Date of Calibration (DOC) for any turndown;