Piezoresistive pressure transmitter for applications in bio-reactors or autoclaves. The transmitter
is compensated up to 150 °C and may be operated continuously or sterilised at this
level, including the special circuit electronics.
The transmitters are supplied in absolute or gauge versions, with current or voltage output.
The sensing component is a micro-machined silicon pressure 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 analogue output signal is generated by a 16-bit D/A converte and updated every 10
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.