Thermometers - Non Touch Infra Red ~ iHealth PT3. An ultra-sensitive infrared sensor that measures the infrared energy emitted by the forehead and collects more than 100 data points per second.. A distance sensor that ensures that measurements are taken no more than 3 cm from the forehead to avoid errors.. An environmental temperature sensor that detects the real-time variations in environmental temperature to reduce the impact and compensates to ensure measurement accuracy.. All this is done with a single button, in just 1 second.