Industry trends

What is a gas sensor?

A gas sensor is a gas sensitive device that can convert the measured gas concentration into a device or device that has a certain relationship with it. It is widely used in smart home, automotive electronics, consumer electronics, wearable devices, medical, industrial processes, Environmental monitoring and other industries.

According to the gas-sensitive material of the sensor and the mechanism and effect of the interaction between the gas-sensitive material and the gas, it can be mainly divided into semiconductor type, solid electrolyte type, electrochemical type, contact combustion type,

Sensor types such as optical and thermal conductivity. Today we will focus on semiconductor gas sensors.

What are the types of semiconductor gas sensors?

According to the physical characteristics of semiconductor changes, it can be divided into resistive type and non-resistive type. According to the changes that occur when the semiconductor interacts with the gas, it is limited to the surface of the semiconductor or goes deep into the interior of the semiconductor, and can be divided into surface control type and bulk control type.

How does the semiconductor gas sensor sense the presence of gas?

The semiconductor gas sensor is a device that uses the mechanism of semiconductor gas sensor and gas contact, which causes the conductivity of the gas sensor itself to change. Resistive semiconductor gas sensor is a sensitive element made of metal hydride material, which uses the change of its resistance value to detect the concentration of gas.。

气敏电阻结构示意图

气敏器件阻值-浓度关系

The non-resistive semiconductor gas sensor uses other parameters, such as diode volt-ampere characteristics and threshold voltage changes of field effect transistors, to detect the measured gas.

Schematic diagram of the structure of a non-resistive gas sensor

l-V Characteristics of Pd-Ti I2 Diodes (25℃)

How to judge the performance of semiconductor gas sensor?

In the early stages of semiconductor gas sensor research, the qualification verification of semiconductor gas sensors can be simplified by using I-V characteristic analysis techniques. According to different materials, the semiconductor gas sensor has a large resistance span, covering the range of Ω~GΩ. To test semiconductor gas sensors with different gas-sensitive materials, an efficient detection scheme is required.

PRECISE high-precision SMU

The high-precision SMU independently developed by PRECISE has the advantages of large dynamic range and high input impedance. It can cover gas sensor test requirements in different resistance ranges from Ω to GΩ, and is the best choice for gas sensor test instruments. like:

①Real-time testing of resistance value response sensitivity of various materials under the same gas condition

②Resistance measurement with a high range span (Ω, KΩ, MΩ, GΩ) at low voltage requires high input resistance of test equipment

③I-V curve scanning

④Support R/t characteristic test of ≤40 channel gas sensitive resistance, and can record and archive.

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