8-channel measurement module for type K thermal elements

April 07, 2013 // By Christoph Hammerschmidt
For data acquisition and measurements in the engine compartments of vehicles, measurement equipment manufacturer Ipetronik GmbH has developed the M-Thermo2 data acquisition unit with eight analog inputs for type K thermal elements (NiCr ( NiAl). The products enhances Ipetronik's range of second generation of CAN-equipped temperature measurement modules.

The new unit comes in an M2 casing with just 106mm x 30mm x 50mm and is protected against splashing water according to IP67. It is designed to operate in the temperature range from -40°C to +125°C and runs off a supply voltage between 6V and 36V. Power consumption is typically 1.1W.

The temperature measurement range is much wider than the operating temperature range: The device measures temperatures between -60° and +1370°C. The input values are digitized by means of a 24-bit ADC. Cold-spot compensation is achieved by means of a PT100 element located directly at the input sockets. At the start of each measurement activity, the A/D converter chain is calibrated. In order to achieve maximum precision, the sensor characteristic is been linearized by means of an internal compensation algorithm, using a hardware RC low pass filter with a base frequency of 1 Hz. Resolution is specified at better than 0.087°C (14bit). Precision at 25°C is 0.035% of the full range.

The modules offers channel sampling rates of up to 100 Hz and a total sampling rate of 800 Hz. Status LEDs at each input inform the user about the correct channel allocation; during operation they indicate if a sensor connection is broken. The data output is achieved across a CAN 2.0B bus according to ISO11898-2 at a bandwidth of up to 1 Mbit/s. All measurement inputs, CAN bus connections, power supply and casing are separated galvanically. In addition, the M-Thermo2 is equipped with a dedicated mechanism that enables users to plug the casings together without tools.

For more information visit http://www.ipetronik.com/en