How to Choose a Proper Alcohol Tester?

While semiconductor or Electrochemical sensors are commonly used in the market for alcohol testers, there are a few manufacturers that use MEMS sensors, and the price of different sensors varies widely.

Fuel cell sensor

The fuel cell breathalyzer reply on chemical reactions. The alcohol concentration on a person breathes is the energy for the fuel cell. The higher the concentration, the more electricity will be generated. The strength of the measures electrical current to determine alcohol content.

Electrochemical sensors provide a high degree of accuracy and repeatability and are not interfered with by other gases. That's why many of the devices used by law enforcement are equipped with electrochemical sensors. But its cost is high and its process complex.

Advantages

• High accuracy: Fuel cell sensors have better accuracy and consistency than semiconductor sensors. Always give accurate values within the test range.
• Specificity: The fuel cell sensor can always remain alcohol-only responsive. Unlike semiconductor sensors, they are subject to other gases. If the user is on a ketogenic diet, the semiconductor alcohol tester will also give a value for the ketone gas detected. This makes the sensor output unreliable and could lead the instrument to trigger false alarms.
• Calibration stability: electrochemical sensors do not need to be calibrated frequently, usually once a year. Semiconductor sensors are prone to baseline shifts over time and the calibration is usually required on a semi-annual basis.
• Reliability: Electrochemical sensors have short preparation time and are not easily affected by previous results. They can be continuously tested. When a semiconductor is being tested continuously, a period of rest is required.
• Long life: The expected life of a fuel sensor is 3 to 5 years.

Semiconductor sensor

Under certain temperature conditions, the gas will chemically react with the oxygen adsorbed on the surface of the semiconductor sensitive material when it reaches the surface and causes a change in the resistance of the semiconductor sensitive material, the rate of change in resistance is exponentially related to the measured gas concentration, the gas concentration can be measured by the change in resistance.

Semiconductor sensors also account for a large share of the market. It provides users with an affordable way to measure alcohol, but with that comes a sacrifice of some accuracy.

Therefore, semiconductor alcohol testing is generally used for personal use or promotional purposes.

Advantages

• Low cost: Low manufacturing costs and simple processes lead to affordable products.
• Portability: The simple structure of the product makes it possible to implement a portable alcohol tester. Some keychain-sized alcohol testers, for example.
• Satisfies some users who want to know their approximate alcohol level without being too precise.

MEMS Sensor

MEMS (Micro Electromechanical System) is the integration of microcircuits and micromachines on a chip according to functional requirements, usually in millimeters or microns in size. MEMS technology uses a range of existing technologies and materials in semiconductor technology.

With the rapid development of MEMS technology, gas sensors have also evolved towards miniaturization, intelligence, integration, and low power consumption.

Microstructured gas sensors using MEMS technology, combining heating elements and sensitive elements. Optimizing the performance of the gas sensor and greatly improving the sensitivity, reliability, and consistency of the gas sensor.

Advantages

• The consistency and accuracy of MEMS sensor better than semiconductors, and close to the fuel cell sensor.
• Sensor arrays and comparative signal processing can increase selectivity to target specific gases. It means the results will more stable.
• MEMS provides a reduction in power consumption. Normally, the power consumption of semiconductor needs around 120 mA, but the MEMS-based sensor only needs 15mA. It means the battery can be used longer.
• MEMS sensor can dramatic size reduction, it also can improve some pocket and handheld semiconductor breathalyzer.

Conclusion

For better quality and accuracy, a fuel cell is certainly an excellent choice for you.

If accuracy is a requirement, but the budget is limited, MEMS will be more suitable for you and relatively profitable, as it is all from private molds.

If you don't require much accuracy, or want to purchase some alcohol testers as promotional products, there are many models of semiconductors available. Although some public models are not very profitable, sales can be guaranteed.