Temperature sensor detects tiny temperature differences

Paul Boughton
Micro-Epsilon is launching a new infrared temperature sensor that is claimed to break new boundaries in terms of low noise and low ambient drift. The Thermometer CSm hs is suitable for measuring extremely small temperature differences down to 0.025 degrees C. According to Micro-Epsilon, alternative sensors currently on the market measure temperature differences down to 0.1 degree C at best.

The very high sensitivity of the Thermometer CSm hs is achieved by utilising a new type of infrared detector material developed by Micro-Epsilon. This innovative thermal and electronic design – which has no moving parts such as chopper wheels – ensures a very low ambient drift and results in a sensor that has a noise level of five to seven times less than alternative thermometers.

Chris Jones, managing director at Micro-Epsilon (UK), comments: "Our biggest challenge has been to find out which customers actually need to measure temperature differences down to this kind of level. We have already had interest from the medical and biological sectors, micro-electronics and glass producers, as well as manufacturers of solar panels, producers of flat-screen LCD displays and semiconductor processing companies."

In the processing of the latest solar panels and flat screen LCDs, for example, special homogeneous coatings are required on the glass and other substrates. Jones explains: "If the temperature of the glass is allowed to fluctuate, the homogeneity of the substrate cannot be guaranteed, which means the end user or customer of a flat-screen TV may discover surface imperfections in the form of inferior or incorrect colours on the display. If the temperature of the glass increases then the sheet of glass extends and the printed dots on an LCD display can end up in the wrong position. It is therefore critical that manufacturers can measure micro- and nano-scale temperature changes in the glass before printing of the substrate takes place.

"The problem with alternative temperature measurement products such as thermal imaging cameras is that if the ambient temperature suddenly increases or decreases by five degrees Centigrade the sensor performance is adversely affected. With our new sensor and its thermally-insulated housing, the object temperature reading is not affected by changes in the ambient temperature."

Despite its thermal shock-proof stainless steel housing, the sensor is very compact, which enables it to be mounted in restricted spaces in a wide variety of industrial applications. The sensor has a standard 4-20mA analogue output and integrated digital interface, enabling it to be integrated with a wide variety of process control devices.

Compactconnect software, which is supplied with the sensor, simplifies sensor set-up and enables the device to be configured remotely. The sensor supports multi-tasking and has a graphical display for temperature trends and automatic data logging tools for analyses and documentation.

Customers can adjust the signal processing functions and programme the outputs and inputs. The sensor even adjusts itself automatically to emissivity, which greatly simplifies the customisation of sensors for individual customer requirements.

For more information, visit www.micro-epsilon.co.uk