Analysis of high and low alarm setting of combustible gas alarm detection range


 Nanjing Aiyi Technology Co., Ltd

Focus on gas and dust detection for 12 years

Service provider of gas detection, gas analysis and dust detection

National free hotline


Current location: home page » technical support » Analysis of high and low alarm setting of combustible gas alarm detection range

Analysis of high and low alarm setting of combustible gas alarm detection range

Article source: AI Yi Technology popularity: - Time of publication: 2016-11-14 10:32:00

 Agh6100f portable combustible gas detector.jpg     

Agh6100f portable combustible gas detector

First of all, let's popularize the alarm value of combustible gas alarm system, and set it as: the default low limit is 25% LEL (5% LEL ~ 40% LEL is adjustable); the default high limit is 50% LEL (10% LEL ~ 100% LEL adjustable).

The setting basis is as follows: the measurement range of combustible gas alarm is 0 ~ 100% LEL, according to the national regulations, the low alarm is generally set between 15% LEL and 25% LEL, and the high alarm is generally set as 50% LEL alarm. Most of the low alarm points of the combustible gas alarm are set at 25% LEL. Here, 100% LEL refers to the explosion limit value of gas, that is to say, when the combustible gas alarm displays 100% LEL, it has just reached the explosion limit of combustible gas.

Now it is necessary to know which kind of gas the tested combustible gas belongs to, such as methane, isobutane, propane, hydrogen, benzene, ketone, alcohol, etc. Secondly, determine the concentration of the gas to be measured. In most cases, the detection of the lower explosive limit (LEL) is generally used. Note: the lower explosion limit of different gases is different, such as 1.8% for isobutane and 5% for methane. Some parts can be detected in ppm (parts per million), 1% = 10000 ppm. If it is% LEL, the range is 0-100% LEL; if it is ppm, it is generally 0-100ppm or 0-1000ppm.

In short, to make clear the type and concentration of combustible gas to be measured, you can choose the corresponding type and range of alarm, the principle is catalytic combustion type. There are countless brands to choose from.

Then the customer asked again, what is the basis for setting low and high reports? Let's talk about this problem today.

We often see that the measurement range standard of combustible gas alarm (gas detector) such as natural gas alarm and liquefied gas alarm is 0-100% LEL. What does 0-100% LEL mean?

When the concentration of combustible gas in the air reaches its lower explosion limit, we call the explosion risk degree of combustible gas environment in this place as 100%, that is, 100% LEL. If the combustible gas content only reaches 10% of its lower explosive limit, we call the ambient explosion risk of combustible gas in this place as 10% LEL. The monitoring of combustible gas in the ambient air often directly gives the environmental risk degree of combustible gas, that is, the percentage of the combustible gas content in the air and its lower explosive limit: [% LEL]; therefore, this kind of monitoring is sometimes called "Explosion detection", the monitoring instrument used is also known as "explosion detector".

The maximum concentration of combustible gas in the air when exposed to open fire is called the upper limit of explosion. English: upper Exploration Limited.

The explosion limit is for combustible gas, which is very important for the setting of gas alarm. Explosion limit is a very important concept, which has great practical significance in fire and explosion protection work. The explosion limit is usually expressed by the volume percentage of combustible gas in the air, or the weight percentage of combustible gas.

The explosion limit is the general term of the lower explosion limit and the upper explosion limit. The concentration of combustible gas in the air will explode only when it is lower or higher than the lower explosion limit.

The explosion limit of combustible gas is divided into upper explosion limit and lower explosion limit. If it is higher than the upper limit, the oxygen content in the mixture is insufficient, and it can not cause combustion or explosion. When it is lower than the lower explosion limit, the combustible gas content in the mixture is insufficient to cause combustion or explosion. The combustion and explosion of combustible gas are also related to gas pressure, temperature, ignition energy and other factors.

Generally, the lower limit of LEL% L is one level alarm, and the second level alarm is 10% L.

The above is the summary of combustible gas alarm professional knowledge, if you have more questions, please consult Nanjing Aiyi Technology Co., Ltd.

 Anjpr. Combustible gas detector

Anr field display combustible gas detector

Nanjing Aiyi Technology absorbed Integrated solutions and Gas detection analyzer , Dust detector , Gas detection alarm , Oxygen analyzer , Combustible gas detector Etc. production, sales, R & D, after-sales one-stop technology service providers Hotline: 400-025-9821

Keywords: Gas detection analyzer, dust detector, gas detection alarm device, oxygen content analyzer, combustible gas detector
真人斗牛app 博狗导航 皇冠体育官网 AG真人网 电玩竞技游戏 皇冠体育app 电玩竞技游戏 电玩游戏平台