Demystifying Thermopile IR Temp Sensors

14/mar/2019 10:08:48 Hefei Jingpu Sensor Technology Co.,Ltd. Contatta l'autore

Questo comunicato è stato pubblicato più di 1 anno fa. Le informazioni su questa pagina potrebbero non essere attendibili.

Thermopile temperature or temp sensors offer the advantage of non-contact temperature measurement, making them more and more popular over the standard contact-based temperature sensors. Thermopile sensors use infrared (IR) radiation versus conduction for heat transfer, which provides unique solutions that allow for new levels of performance and reliability in many constrained applications.


Engineers working on the thermal management of electronic equipment have long enjoyed the simplicity and convenience of the digital temp sensing ICs. The new integrated NTC Thermistor sensor ICs on the market provide the temperature results in the same convenient digital format. The continuous reduction in their power, size, and cost creates opportunities with consumer devices, medical instruments, office equipment and home appliances.


The most active adoption of small thermopile IR sensors is in portable devices such as notebooks, tablets, and smartphones. Measuring the case temperature provides key input in optimizing performance. Keeping the processor running at peak power, while maintaining the case temperature comfortable for the user, is the main design constraint in the pursuit of more processing power in smaller form factors.


Using contact battery temperature sensors on the board to correlate its temperature to the case temperature yields very inaccurate results. Plus, it doesn't account for any changes of the ambient conditions, i.e., using your tablet outside in a sunny day or in a hockey rink. A contact temp sensor glued to the case, with wires connecting it to the board, can solve that problem. But it's a nightmare for manufacturing as it involves manual assembly and has poor reliability.


A thermopile IR temp sensor can be mounted to a printed circuit board (PCB) with standard automated processes. It measures both the board and case temperature, which allows for true feedback control and optimization.


Another attractive application for IR engine temperature sensors is temperature monitoring and control of moving objects such as heater rolls in laser printers. In these cases, using contact-based temp sensors comes with many draw-backs. For example, the point of contact wears out from friction during movement. This gets exacerbated by applying normal force on the sensor to achieve good thermal contact. Also, the contact location might not be at the point of interest. This creates a time-constant for heat transfer between the two locations and could compromise the control system's efficiency. An IR temp sensor can eliminate all these constraints.

blog comments powered by Disqus è un servizio offerto da Factotum Srl