ACS Precont S, Technical Manual

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Precont S
page 3 of 28
Application description
The devices of the series Precont S with integrated digital evaluation electronic are compact pressure
transmitter for continuous measuring and surveillance of pressures from –1 up to 1000 bar within gases, vapors,
liquids and dusts within closed container or pipelines, also in explosive hazardous areas, at process
temperatures from – 40°C to +370°C.
The use of a capacitive measuring sensor with ceramic membrane or of a strain gauge with metallic membrane,
by use of various, also front flush process connections resp. process diaphragm seals, allows the use in nearly
all fields of industry, especially also in hygienic applications.
Function
The device is used for pressure measurement.
Characteristics of the ceramic measuring membrane – Precont S10 / S40 / S70
The system pressure is applied to the ceramic membrane and causes there a variation of the capacity at the
back side of the membrane.
A pressure transmitting liquid is not used.
The ceramic membrane offers excellent characteristics like highest pressure and pressure blow strength up to
forty times the nominal pressure, vacuum resistance, very high resistance against chemicals, corrosion and
abrasion as well as very good insensitiveness against temperature shocks, highest accuracy and reproducibility,
good long term stability and a very low temperature influence.
Characteristics of the metallic measuring membrane – Precont S20 / S30 / S70
The system pressure is applied to the metallic membrane and causes there a deflection of the strain gauge at
the back side of the membrane.
A pressure transmitting liquid is only used at pressure ranges lower than 0...25 bar.
The metallic membrane offers excellent characteristics like high pressure and pressure blow strength up to six
times the nominal pressure, vacuum resistance, good reproducibility and hysteresis and also good long term
stability and a low temperature influence.
Characteristics of the process diaphragm seal – Precont S70
The system pressure is applied to the metallic membrane of the process diaphragm seal and is transmitted by a
pressure transmitting liquid to the respective ceramic or metallic measuring membrane that is placed behind.
This leads among others to a extension of the permissible medium temperature up to +370°C and to an
essential increase of the temperature stability of the device.
Signal processing
The pressure dependent variation of capacity resp. the variation of the strain gauge output voltage is recorded in
high resolution by a processor, adjusted acc. to the settings and converted in high resolution into an output
signal of 4...20mA or 0...10V.
According to the resp. settings the PNP switching outputs are driven.
The switching state of the two PNP switching output are indicated by each an LED.
By 3 keys and the four digit LED display all settings for the display, the analogue output as well as the PNP
switching outputs can be set resp. adjusted.
A transmitter fast adjustment per key combinations is also possible.