Low-cost, low-power universal resistance measurement circuitry to interface commercialized resistive gas sensors.

Semiconductor and electronics miniaturization capabilities has increased the functionality of sensing devices to detect multiple types of gases in the environment and is resulting in a change in the gas sensor market segment. One issue around the use of sensor array technologies has been the ability to effectively interface between the sensors and the communication apparatus either on the sensor or elsewhere.

Researchers at the University of Utah have developed a novel technique to provide a singular interface that can effectively work with multiple sensors, especially of the highly resistive type. The architecture of the interface features different capacitor and gain ranges for high dynamic range. The circuit has automatic toggling between ranges for seamless interfacing without required configuration and automatic calibration for best in class reduction in measurement error.
Additional benefits such as lower cost and lower power capability of the design, along with a universal resistance measuring circuitry, allow for interfacing with a variety of commercially deployed resistive gas sensors.

Benchtop Prototype

• High stability and non-saturation during measurement of air and other gas concentrations
• Directly interface to the sensor and convert resistance values into a frequency that can be more easily transmitted via the UART interface
• Benefits such as increased sampling frequency, measurement error and dynamic performance
• Handles resistance ranges from 5 kΩ to 50 GΩ with less than 0.35% in measurement error

Dean Gallagher
(801) 585-0396
dean.gallagher@utah.edu