Thermistors for digital thermometers and sensors for wearables


Digital thermometers are being widely used today but were so expensive when they first hit the market, that they never became widespread initially. Not only were the prices of electronic components that had been used very high, but it was also difficult to mass-produce small thermistors suitable for digital thermometers and was necessary to adjust the temperature of each thermometer individually. This made it quite challenging to make the products affordable in the beginning.

Efforts to address challenges

SEMITEC was the first manufacturer in the industry to achieve mass production of miniature thermistors (ET series) and provide high-precision temperature classification. This has allowed us to eliminate the need for temperature calibration of each thermometer, and thereby contribute to significant cost reductions. As the convenient and easy-to-buy digital thermometers quickly became popular, global usage of ET thermistors in digital thermometers and basal digital thermometers grew to approximately 80% at one point. Our products have evolved further, and now the latest ET-3H series thermistors are being widely adopted in the same thermometer applications.

To further meet the evolving needs of digital thermometers, we have developed the miniature FT-ZM series thermistors which utilize our proprietary thin-film technology. The FT-ZM delivers a 70% increase* in response time over conventional thermistors and is used in high-performance digital thermometers including the high-speed types. In addition, by making full use of temperature measurement and MEMS technologies that were developed through producing thermistors for digital thermometers, we have designed and developed thermopiles for ear (tympanic) thermometers. These are non-contact infrared temperature sensors which have also been widely used in forehead thermometers that have been key devices under the COVID-19 pandemic. With the growing demand for sensors used in wearables such as for disease prevention, daily health management, heatstroke prevention and monitoring, SEMITEC will contribute to building a healthy society through offering its sensors for wearables.

* Based on SEMITEC’s internal evaluation