Improved infrared temperature sensing system for mobile devices

Kimmo Keränen, Jukka-Tapani Mäkinen, Pentti Korhonen, Eveliina Juntunen, Veli Heikkinen, Jakke Mäkelä

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    1 Citation (Scopus)


    An infrared (IR) temperature measurement system consists of not only a sensor module and electronics, but also an optomechanical system that guides IR radiation onto the sensor. The geometry and emissivity of the parts affects the reading, if the detector sees not only the target but parts of the measuring system itself. In normal industrial applications, the optics is designed so that the surfaces stabilize to the same temperature as the sensor. This allows the error caused by the device temperature to be easily calibrated away. The correction is valid for stationary conditions and usually near the calibration temperature, which is typically at room temperature. However, we show that if the sensor is embedded into a mobile (hand-held) device which has heat sources, such as power electronics, the normal conditions are no longer valid and the calibration fails. In order to improve infrared temperature sensing for mobile devices, the optics concept was studied and detailed design was performed. In addition, the optics performance was modelled and verified by measurement sensor prototyping. A calibration procedure noticing operational temperature variations was applied. The repeatability of the implemented IR temperature sensor using on a correct transferred calibration curve was better than ±0.5 °C in an operational temperature range from +12.6 to +49.3 °C and target range from +10 to +90 °C.
    Original languageEnglish
    Title of host publicationProceedings
    Subtitle of host publication2nd Electronics Systemintegration Technology Conference, ESTC 2008
    Place of PublicationLondon
    PublisherIEEE Institute of Electrical and Electronic Engineers
    ISBN (Print)978-1-4244-2813-7, 978-1-4244-2814-4
    Publication statusPublished - 2008
    MoE publication typeA4 Article in a conference publication
    Event2nd Electronics System-Integration Technology Conference, ESTC 2008 - Greenwich, United Kingdom
    Duration: 1 Sept 20084 Sept 2008


    Conference2nd Electronics System-Integration Technology Conference, ESTC 2008
    Abbreviated titleESTV 2008
    Country/TerritoryUnited Kingdom


    • Temperature
    • infrared measurement sensor
    • mobile device
    • calibration


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