To select the right gas detector

What do we need to consider to find a suitable gas detector? you can refer to the following aspects.

1. Detection principle of sensor: Traditional electrochemical sensors and semiconductor sensors can measure many kinds of gases, and the sensor technology is mature and the price is low, but it's detection accuracy is low and the response time is slow, and it is easy to be interfered by other gases and environmental factors. The sensor based on solid state electrochemistry has better sensitivity and accuracy and it's also has low price. The non-dispersive Infrared Absorption Principle (NDIR) sensor has good sensitivity and accuracy, but it is expensive, and it can currently detect only a small subset of gas types, such as CO2, CH4, and some hydrocarbons.

2. Accuracy and sensitivity of the detector: Look for gas detectors with high accuracy and sensitivity. This can be determined by looking at product specifications or certification marks, such as ISO 9001 certification and CE marking. In addition, try to select gas detectors that are adjustable and capable of detecting lower concentrations to better protect the health and safety of production personnel.

3. Reliability and lifespan: Select a gas detector with good reliability and a long lifespan. Knowing the warranty period of the detector, as well as reviews and feedback from other users, it can help you judge the reliability of a product.

4. Functionality and ease of use: Consider the functionality and ease of use of the detector. Some products may have data recording and analysis capabilities, while most products may merely provide a basic display of gas concentration. Confirm whether sound, light, vibration alarm is required according to the demand. Adjustable alarm threshold is convenient.

5. Price and brand reputation: Consideration of price and brand reputation is also necessary. Price usually reflects the quality and performance of a product, but it's also important to compare the differences between brands. Checking the brand's reputation and customer reviews can help you select a reliable gas detector.

The working principle of an electrochemical gas sensor is shown below,

The principle of electrochemical gas sensors involves a three-electrode design, enabling continuous application in gas concentration measurement. The sensor primarily consists of a three-electrode system (working electrode, counter electrode, reference electrode) and a liquid electrolyte, operating under a constant potential. Gas molecules diffuse through pores to reach the working electrode of the sensor, where electrochemical reduction reactions occur on the electrode surface. The protons resulting from the reaction migrate to the counter electrode through the polymer electrolyte, and the magnitude of the current signal is directly proportional to the concentration of the measured gas. According to Fick's law, i = nFDC. Therefore, the current flowing is directly proportional to the concentration of the target gas, while the reference electrode maintains a constant potential with the potentiostat.

Here are some Features and Characteristics of Solid-State Electrochemical Gas Sensors,

1. High sensitivity: Capable of high-resolution detection at the PPB level with a resolution of up to 1ppb, allowing continuous exposure and monitoring in high-concentration gases.

2. Quick response: The sensor's response time can be within 3 seconds, with T90 30s.

3. Good stability: Long-term use does not result in issues such as zero drift.

4. Long lifespan: Using non-consumable solid-state electrolyte technology, the sensitivity degradation is minimal during long-term use.

5. Compact size: Enables the application of multi-parameter integrated devices and integration into portable and wearable devices.

6. Strong anti-interference: With the use of special catalytic electrode preparation technology, it has strong anti-interference capabilities, avoiding interference from other gaseous substances.

7. Wide temperature range: Can operate normally in environments ranging from -40 °C to 55 °C.

8. High linearity: Full-range linear measurement, satisfying high precision with <±5%FS.