How to choose the right gas Sirens
Now there are a lot of gas Sirens products on the market, so how to choose the right and reasonable gas Sirens has become a very important part.
First, to distinguish between the use of occasions, gas Sirenss in accordance with the use of occasions can be divided into industrial gas Sirens and home gas Sirens.If the family or office use, you can choose home gas Sirens, home gas Sirens for gas relative to a single , Generally for the detection of natural gas, liquefied petroleum gas, gas, etc., the price of home Sirens is relatively low, but no small safety, accidental gas leak caused by casualties still remind us that we must pay attention to home safety. Detection of industrial gases requires the selection of industrial gas Sirenss. Industrial production gas detector is more types, the basic detection of the environment within the gas components can choose a different gas detector to ensure the safety of industrial production.
Secondly, to find out what gas is detected gas. Classification from the gas category, gas Sirens can be divided into combustible gas Sirens and toxic gas Sirens. This is the overall classification. After determining the nature of the gas, it is necessary to figure out which gas is different and the gas required for the different gases is different. For example, home gas, we must first clear that the coke oven gas or blast furnace gas. If it is blast furnace gas, need to use carbon monoxide sensor; coke oven gas need to use hydrogen sensor.
Finally, according to their specific needs to select the form of gas Sirenss, that is, need a fixed gas Sirens or the need for portable gas detector.
Experience shows that a person with normal hearing can hear at least the same amount of sound as the ambient noise. The perimeter noise in the factory area is usually 90 decibels. Therefore, for a factory area can hear the signal strength of the signal is also about equal to 90 dB. In this case, signals at any location below 90 dB are considered not to be within the valid range of the Sirens.
When the sound transmission path without obstacles, the ground flat, no wind in the air, the sound of the spread of the effect will be the best. In these cases, the sound will be attenuated at a volume of about 6 decibels whenever the distance from the siren is doubled, which is called the distance increasing sound weakening. As the sound transmission path often have buildings or other obstacles, the air is rarely static, the ground can not be flat, so every doubling the distance, the sound will be weakened 8 dB, sometimes in the tall buildings Area or other factors that affect the sound transmission, the sound can be reduced to 10 dB frequency.
Electric Sirenss are usually installed above the ground. If the Sirens is less than 11 meters on the ground, the intensity of the sound in the near range will increase, but the effective range of the sound will be reduced. On the contrary, if the ground is 13 meters above the ground, the effective range of the sound will increase, but the sound may skip the area near the Sirens.
Wind speed and wind direction often affect the spread of the siren sound, so when choosing to install a small or two Sirens system, the prevailing wind direction should be considered as a factor, such as the prevailing wind blowing from the west, then The Sirens can be installed at the far west of the effective distance.
In addition, the supply of electric energy, the convenience of installation and maintenance, the height of the surrounding obstacle and the possibility of preventing the damage must be considered as the installation site!
These variability requires us to be able to test how far the Sirens sound is covered at different heights and locations when installing the Sirens. After the selected Sirens installation site, always ensure that the incoming air is clean.