The basic principle of metal oxide sensors is the resistance of detection layer changes at the presence of the targeted gasses. Oxidizing gases such as ozone or nitrogen di-oxide the resistance will increase and gases such as carbon monoxide the
This is the SFM3000 a Mass Flow Meter develop by SENSIRION. This can measure a bidirectional flow of air and other non-aggressive gases at rate up to 200slm superb accuracy and extremely high speed output at 14 bit/ 2kHz rate.
This is the BH1790GLC an Optical Hearth Rate Monitor Sensor developed by ROHM semiconductor. This sensor has an integrated optical and LED driver design to detect green light photo diode. This device drives LED and provides an intensity of light
BME280 is an integrated digital humidity, pressure and temperature sensor. This sensor module is compact in a small smart integrated device on a metal-led this device runs on a low power consumption that allow the sensor driven in a battery