When an N-type oxide is exposed to the atmosphere, it decreases the number of electrons it contains and increases its resistance due to the adsorption of oxygen.
Subsequently, when a certain reducing gas is in the atmosphere, it reacts with the adsorbed oxygen, increasing the number of electrons in the oxide, resulting in a decrease in the resistance of the oxide. The semiconductor oxide sensor analyzes the gas concentration by changing the resistance value.
The Breathalyzer actually consists of an alcohol gas sensor (equivalent to a rheostat that changes with the concentration of alcohol gas), a fixed value resistor, and a voltmeter or ammeter.
R1 is a fixed value resistor. The resistance value of the alcohol gas sensor R2 decreases as the alcohol gas concentration increases. If the concentration of alcohol gas exhaled by the driver is greater, the Tester The voltage indicates the larger the number.
Let's take the breathalyzer as an example: If the alcohol content of the driver's exhaled air exceeds the prescribed limit, the instrument's vibration motor vibrates and the indicator light flashes.
In addition, this traffic police breathalyzer has a very high sensitivity. The detection efficiency is extremely high and the result can be obtained within 1 second.
The instrument can also store 80,000 test records including date, time, temperature and alcohol concentration. It is the best choice for continuous testing by multiple people. The driver does not have to wait for a continuous inspection, saving time and effort.