Test bits

More tolerance

To address evolving temperature-measurement technologies in industrial applications, the International Electrotechnical Commission (IEC – www.iec.ch) has published the second edition of IEC 60751, its standard on industrial platinum resistance thermometers and platinum temperature sensors.

Most temperature measurements in the range below 400°C are performed with industrial resistance thermometers. IEC 60751 defines minimum requirements on the quality of these thermometers, which leads to different tolerance classes. The relation between the temperature and the electrical resistance of the thermometer is defined in the IEC Standard, which allows the replacement of sensors independent of their manufacturers.

Tolerance classes are now given separately for resistance sensors and thermometers, as well as for wirewound resistors and film resistors. The number of tolerance classes has been increased from two to four, and the tolerance acceptance test now takes into account the measurement uncertainty of the test.

Special thermal needs

If off-the-shelf temperature measurement products don’t have exactly what you need, take a look at the integrated thermal sensor tutorial and application pages on Microstar Laboratories’ Web site (www.mstarlabs.com/sensors/temperature.html). The new section of the site shows you how to implement high-performance temperature measurement systems so you don’t have to put in time and effort to pull together information from various places on the Web. You also can also download the material formatted as a PDF file.