Matchstick figures
8 May 2003
Small enough to fit on the head of a match, Hero Electronics' Sensirion digital integrated humidity and temperature sensor boasts response times of less than four seconds.
Its speed results from the gold-plating on its reverse side, which ensures good heat transfer to the sensor elements.
The SHT75 sensor uses a two-wire digital interface and operates from -40 degrees C to 120 degrees C, with 2 per cent RH accuracy and 0.5 degrees C temperature accuracy (although a cheaper unit is also available with 3.5 per cent RH).
The narrow bridge between the sensor head and pins provides good thermal isolation. Each sensor is individually calibrated, with data stored on the onboard control electronics.
