These pressure transmitters have conventional analogue outputs but are designed for industrial
applications where the highest accuracy is required. They combine the latest technologies
of both pressure sensor and electronic compensation.
The pressure sensor is a high stability piezoresistive device designed for use in transmitters
where accuracy and stability are essential. The sensor is selected after severe testing under
pressure and temperature. The sensing component is a micro-machined silicon chip of high
sensitivity mounted in a floating arrangement. An independent temperature sensor is integrated
on the surface of the silicon chip.
The processing electronics comprise a PIC 14000 microprocessor with an integral 13…14 bit
A/D converter and inputs capable of handling 5 signals. Conversions are performed at a rate
of at least 100 operations per second.
The pressure signal compensation uses a mathematical model based on polynomial approximation,
which provides almost perfect compensation over the operating temperature range.
The voltage (or current) analogue output signal is generated by a 16-bit D/A converter. The
output signal is updated every 10 milliseconds.
The user can, via the RS485 interface and using a KELLER adapter cable, set the zero and
the gain of the transmitter by simple software programming.
The transmitter has great manufacturing flexibility and can be produced with various types of
pressure connection. Among its features are standard plates which hold the connector, enabling
the same transmitter to be supplied with different electrical connectors that can be exchanged
by the user as an option.