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WIKA operating instructions pneumatic high pressure controller, model CPC7000
0019104001D 10/2018EN
EN
9.2.8 Two Point Cal Application
The Two Point Cal Application provides a place to adjust the Transducer Zero and Span (sometimes referred to as the
offset and slope).
Figure 9.2.8 Two Point Calibration App
Follow the steps below for a complete Two Point Calibration:
Select a Transducer to calibrate by pressing the Range button at the top of the screen.
To calibrate the “Low Point”:
1. The Measure/Control port of the CPC7000 being calibrated should be supplied with a suitable, “Low point” pressure (see
section 5.4 - Rear Panel for the port location).
2. For a gauge transducer, this low point pressure can be achieved by opening the Measure/Control and reference ports to
atmospheric pressure.
3. For an absolute transducer a suitable source of vacuum should be applied to the Measure/Control port along with a high
accuracy vacuum standard or a pressure calibration standard can be connected to the Measure/Control port that can generate
and measure a stable pressure value between 600 mTorr absolute and 20% of the active transducer’s span.
4. When the pressure is stable, record the live reading shown on the Two Point Cal screen and enter this value as the “Low
Reading” by pressing the Low Reading button and entering the number followed by the check mark [
]. Record the “true
pressure” obtained from the reference standard and enter it as the “Low Reference” value in the same manner.
To calibrate the”High Point”:
5. The “High Point” Calibration is done in a similar way as the “Low Point”.
6. Supply a pressure to the Measure/Control Port of the CPC7000 being calibrated, using a pressure standard. This pressure
should be as close as possible to the full scale value of the selected transducer or at least within 20% of the active transducer’s
span.
7. After the pressure stabilizes, record the live reading shown on the Two Point Cal screen and enter this value as the “High
Reading” by pressing the High Reading button and entering the number followed by the check mark [
]. Record the “true
pressure” obtained from the reference standard and enter it as the “High Reference” value in the same manner.
8. After all four values (High Reference, High Reading, Low reference, & Low reading) have been entered, the Adjust button will
become active. Press the Adjust button to check and accept the calibration data then press the Save button. The instrument will
then prompt with the question “Save Cal Data?”. Pressing the check mark [
] in this screen will save the calibration to the
memory of the transducer.
9. Maintenance and Recalibration
