This is a non-contact IR temperature sensor which uses Infrared radiation to calculate the temperature of something at which it is pointed.
- Voltage range: 3.3-5V
- Temperature range: -70 to +380 °C, (0.01 ℃ resolution)
- Measurement Accuracy: ±0.2℃(body temperature range)/ ±0.5℃ (ambient)
- Chip: MLX90614 with 17 bit Analogue to Digital (ADC) Converter
This sensor requires the Pin swap module to be inserted between two 4-wire jst leads connecting the peripheral to the Kookaberry. This is because the pin arrangement on the sensor module does not match the pin arrangement on the Kookaberry
How does it work?
The IR temperature probe consists of an optical system, thermopile, amplifier, signal processing, and output module.
The optical system collects all the radiation reflected from its target, and concentrates it on a thermopile which is a connected array of thermocouples. Thermocouples consist of two different types of metals, joined together at one end. When the junction of the two metals is heated or cooled, a voltage is created that is proportional to temperature.
A layer of black material is placed behind the hot end of the thermocouples which absorbs the infrared wavelengths (700 to 14,000nm) being radiated from the target and heats up. This, in turn increases the temperature at the hot end of the thermocouple and the current generated by the thermopile increases proportionally.
This current is then amplified and sent to a signal processing circuit where it is is converted into a temperature value, then into a digital signal and finally sent to the Kookaberry over a four-wire connecting lead.
The MLX90614 integrated circuit chip is self calibrating and has a low noise amplifier integrated into the signal processing chip. The chip itself is a 17 bit ADC and DSP device, giving accurate and reliable results.
Where are they used in real life?
IR sensors operating in this frequency range (700 to 14,000nm or 0.7 to 14 microns) are most commonly used in
Household Electrical Appliances
Control of ovens, cooking appliances, heating elements, irons, refrigerators, freezers and air conditioners.
Control of heating and thermal isolation of the passenger compartment, and windscreen de-icing.
Measurement of the surface temperature of the human body (eg, ear thermometer). This is the sensor used in the temperature “guns” used to quickly take your temperature in COVID screening centres.
Detection of plant and farmland diseases and transfer of heat in plants.
Detection of hot spots in motors indicating a faulty bearing