What is alcohol sensor
The alcohol sensor is a pivotal component in alcohol detectors. When a person exhales into the alcohol detector through a test mouthpiece, the alcohol sensor reacts to the exhaled gas, impacting the accuracy of alcohol detection. This article delves into the nature of alcohol sensors, their types, and variances.
Types and differences of alcohol sensors
There are two primary types commonly used: the fuel cell type (electrochemical type) and the semiconductor type, both of which can be configured into portable breath alcohol testers for on-site usage. Semiconductors are predominantly used in the civilian market, while the electrochemical type finds its application in law enforcement and traffic police departments, particularly abroad.
Semiconductor sensors employ tin oxide semiconductor technology. These devices exhibit gas-sensitive properties. As the concentration of the gas they are sensitive to increases in the exposed gas, their external resistance decreases. Breath alcohol testers using semiconductor technology capitalize on this principle. Different gases at different operating temperatures affect these semiconductors’ sensitivity. Thus, all semiconductor breath alcohol testers include heating elements to raise the sensor’s temperature, optimizing its sensitivity to alcohol.
Fuel cell breath alcohol testers utilize a fuel cell alcohol sensor as the gas sensor, belonging to the electrochemical type. Fuel cells, a globally studied environmentally friendly energy source, directly convert combustible gases into electrical energy without generating pollution. An alcohol sensor is merely one application of fuel cells. Fuel cell alcohol sensors feature precious metal platinum electrodes and a combustion chamber filled with a special catalyst. This setup efficiently burns alcohol entering the chamber, converting it into electrical energy. The voltage generated across the electrodes is directly proportional to the alcohol concentration of the gas entering the combustion chamber, forming the fundamental principle of fuel cell breath alcohol testers.
Compared to semiconductor types, fuel cell breath alcohol testers offer distinct advantages in stability, accuracy, and resistance to interference. Unfortunately, manufacturing fuel cell alcohol sensors demands precise structural requirements, rendering production challenging. Currently, only a few manufacturers in Europe, America, and China can produce them due to their high material cost, which is several times greater than that of semiconductor alcohol sensors. Consequently, the price of a fuel cell alcohol tester is significantly higher, making it several times more expensive than a semiconductor alcohol tester.