Design Example of a 1.5V-Powered, Oxygen Sensor Signal Conditioning Circuit . Oxygen sensors (O2 sensors) are commonly used in life safety and industrial applications. In life safety applications, O2 sensors are used to ensure that adequate levels of atmospheric oxygen are available in any confined space such as an inside an aircraft, in a lab, or in the field. In industrial applications (for example, in the vacuum packaging of food products), O2 sensors can be used to measure the absence of atmospheric oxygen to make sure bacterial growth is inhibited. In all cases, O2 sensors may be part of a portable handheld or body-mounted instrument – where low power consumption is essential – or as a part of a larger, embedded system. Although this design example is specific to an O2 sensor, the application circuit development here equally applies to other types of low-frequency or dc sensors. Oxygen sensors (O2 sensors) are commonly used in life safety and industrial applications. In life safety applications, O2 sensors are used to ensure that adequate levels of atmospheric oxygen are available in any confined space such as an inside an aircraft, in a lab, or in the field. In industrial applications (for example, in the vacuum packaging of food products), O2 sensors can be used to measure the absence of atmospheric oxygen to make sure bacterial growth is inhibited. In all cases, O2 sensors may be part of a portable handheld or body-mounted instrument – where low power consumption