87
WIKA operating instructions pneumatic high pressure controller, model CPC7000
0019104001D 10/2018 EN
EN
12. Accessories
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Barometric reference sensor (for gauge or absolute emulation)
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Additional transducers
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Rack mounting kit
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Fittings
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Pressure booster
12.1 Barometric Reference Sensor
The CPC7000 can be ordered with a barometric reference sensor. It is a very stable, absolute pressure transducer, used to
accurately measure local atmospheric pressure. It is used to display the barometric pressure (reading appears on the bottom right
side of the display) or as a barometric reference for gauge or absolute emulation.
12.1.1 Gauge Pressure Emulation
In the Home Application (main screen) an absolute transducer will indicate “Absolute” in the Pressure Type button (this is the
default mode). When the Pressure Type button is pressed the button label will toggle to “Gauge” and have a lighter background
color. The lighter background color is an indication that the instrument is in emulation mode.
In the gauge emulation mode the atmospheric pressure reading from the barometric reference transducer is subtracted from the
absolute pressure reading of the instrument to emulate a gauge pressure.
The barometric reference transducer has six significant digits. If a very low pressure gauge transducer is active and is used in
absolute emulation, the combined output may appear quite noisy because of the resolution of the barometric reference.
12.1.2 Absolute Pressure Emulation
In the Home Application (main screen) a gauge transducer will indicate “Gauge” in the Pressure Type button (this is the default
mode). When the Pressure Type button is pressed the button label will toggle to “Absolute” and have a lighter button background
color. The lighter background color is an indication that the instrument is in emulation mode.
In the absolute emulation mode the atmospheric pressure reading from the barometric reference transducer is added to the gauge
pressure reading of the instrument to emulate an absolute pressure.The instrument is only able to emulate absolute pressures
above atmospheric pressure. Sub-atomospheric control is not possible.
12.1.3 Emulation Mode Accuracy
The accuracy in emulation mode is different for gauge and absolute emulation mode.
The barometric reference has six significant digits and has a guaranteed drift of 0.0000041 psi over a 24 hour period which has no
significant effect on the emulated gauge pressure uncertainty.
The absolute uncertainty of the barometric reference must be considered in the emulated absolute pressure uncertainty.
12.1.4 Barometric Reference Calibration
The Barometric Reference Transducer can be calibrated in exactly the same manner as the other installed transducers as
described in Section 9.2 Recalibration.
12.2 Additional Transducers
A secondary transducer and a tertiary transducer of any standard range, can be purchased as an option. In all other regards, the
add-on transducer will meet all of the specifications and operating parameters outlines throughout this manual.
The tertiary transducer must be within the range of the secondary transducer and the secondary transducer must be within the
range of the primary transducer installed in the instrument.
12. Accessories
