Keller Series 4 LC...9 LC pressure transmitters

The Keller Series 4 LC to 9 LC pressure transmitters offer two output signals: a ratiometric analog voltage output and a digital inter-integrated circuit interface (I²C). The ratiometric signal eliminates the need for a voltage reference in the support electronics to the A/D converter, with no additional effort for compensation and calibration. For a voltage supply of 5 V, the output signal is specified as 0.5 to 4.5 V. The transmitters provide constant protection against overvoltage and polarity reversal on all lines up to ±33 VDC.

Up to 128 OEM transmitters in the series can be addressed successively by one I²C interface in order to call up the current pressure and temperature values from the transmitters (slaves). With an I²C output, the pressure transmitters can operate with a voltage supply of only 2.7 to 3.6 VDC, and they are ready to supply the current measured values 5 ms after switching on. On/off operation and low power consumption make the transmitters suitable for mobile applications.

With an analog output, the transmitters can be used at temperatures of between -40 and +150°C, and with an I²C output the range is from -40 to +80°C. The full scale pressure ranges for the analog version extend from 2-1000 bar and, for the digital version, from 2-200 bar. The internal sampling rate offers a dynamic range of 2 kHz. Low power consumption during continuous operation is another benefit, with the digital version requiring less than 3 mA and the analog version requiring about 8 mA.