Low-Cost Thermocouple Measurement Module With 24-Bit Delta-Sigma ADC

The thermocouples are automatically linearised on-board, which means that the Celsius values are transmitted to the PC with an accuracy of (typically) 0.1 degrees. This temperature data acquisition module sets a new benchmark for accuracy, at a price of only 645 euros. It is supplied including the QuickDAQ2013 data logger software.

The DT9828 model achieves sampling rates of up to 600 Hz. Screw terminals allow the quick and easy connection of the supported thermocouple types B, E, J, K, N, R, S and T.

The 24-bit A/D converter, the cold junction compensation feature, and the automatic gain and offset calibration on every power-up ensure a high measurement accuracy. All analog measurement channels are isolated from the USB ground. The two digital I/O ports, which each provide four inputs and four outputs, are also galvanically isolated from the bus and the analog channels. The digital inputs support the connection of TTL levels as well as 12 V or 24 V levels; the open collector outputs have a switching capacity of up to 30 V to drive relays directly.

Running entirely on USB power, the data acquisition module is ideally suited for use as a portable device. It includes Data Translation's new QuickDAQ2013 data logger software. Combined with this application, the module offers users a ready-to-measure solution for acquiring, displaying and saving data, and for exporting it to an Excel file. In addition to many 32/64 bit drivers and software tools that are compatible with the standard Windows operating systems, the package also comprises interfaces for LabVIEW and MATLAB.