The difference between different principles of VOC gas detectors

As we all know, there are many detection principles for gas detectors.

There are three main types of VOCs.

As one of the two major categories of gases (toxic and harmful and flammable and explosive), VOC has roughly three detection principles.

The one that everyone comes into contact with most often is electrochemistry.

Regardless of whether it is a solid-state electrolyzer or a liquid electrolyzer, the electrochemical principle requires the participation of oxygen in the reaction, which is displayed by the electrode plates.

For electrochemical sensors, they can be used longer if they do not explode. If they do explode, their service life is generally two years.

But what many people don’t know is that electrochemical sensors can only measure gases contained in more than two dozen VOCs.

At the same time, PID can detect more than 100 types.

The wide range of applications of hydrocarbons has led to separate regulations for them both at home and abroad.

Abroad, the concentration of Class I (matt) paint shall not exceed 30g per liter, and that of Class II (glossy) paint shall not exceed 200g per liter. The domestic requirement is that the concentration shall not exceed 100g per liter.

PID photoionization has a light source that can generally be used for 5 years (ultraviolet light), but the lamp post is easy to break, and as a wearing part, it costs about one thousand yuan to replace it.

According to the domestic Environmental Protection Bureau regulations, PID is generally the minimum requirement, but because many people sell inferior products as good ones, the market is rather chaotic.

FID, hydrogen flame ionization, is also sought after by many people because both electrochemistry and PID can only measure the total amount of VOC, while FID can display a variety of different gases.

But to be honest, domestic FID is still not as good as imported ones. The editor's company is an agent for a German brand. It has a complete range of convenient and fixed types, but they cost hundreds of thousands of yuan, which makes people run away after asking the price, haha.

Okay, that’s all for today.