With the gas, liquefied petroleum gas, natural gas and other combustible gases have been widely used in households, once these gases leak in the use process, it will cause poisoning, fire, explosion accidents, seriously endangering people's lives and property safety. As an important gas detector, gas leakage alarm can detect the content of some gases in the air in a timely and reliable manner, take effective measures to remedy in a timely manner, take correct treatment and disposal methods to reduce the accidents caused by leakage, which is the necessary condition to avoid causing major property and casualties.
At present, there are many brands of gas leakage detection alarms in the market. What factors should users consider when selecting them? The following is a brief introduction to the reference before selection with reference to technical indicators and technical parameters:
1. Response time
(1) Response time: refers to the time interval from the time when the alarm is triggered to the time when the system displays the detected gas. It is the most basic index to measure the function of alarm system. An alarm must have the ability of detection and be able to display the detection results in a proper way in a timely manner.
(2) Alarm response: time interval from the alarm on site to the alarm status displayed in the control center. It includes the delay of alarm, the establishment time of communication and the delay of control system equipment (generally sound and light display).
(3) Alarm confirmation time: the time interval from the on-site induction of the alarm to the confirmation of the alarm by the control center. It includes the time spent in alarm response and review process, such as on-site monitoring, remote receiving time, etc. This process can also include the communication time for the control system to send alarm and relevant information to the superior alarm center. In addition, the starting time of the linkage can also be regarded as the response time. Such as the time interval from the detector on-site alarm to the control linkage (such as closing the solenoid valve to cut off the air source, and opening the exhaust fan, etc.). Generally, the alarm response is very short. Therefore, in the specific inspection, it is appropriate to measure the alarm confirmation time or system response.
2. Detection area and detection sensitivity security system usually take detection area and detection sensitivity as the evaluation index of alarm detection, which is different from PPS.
(1) Detection area: a certain range of security system design. When the gas reaches the alarm concentration in this range, the detector will detect in time and send out the alarm signal.
(2) Detection sensitivity: the detector's sensing ability to gas leakage at the installation site, usually less than 25% of the lower explosion limit of different gas alarm concentrations. Compared with the traditional contact combustion sensor, the most outstanding feature of the semiconductor normal temperature sensor used in the gas alarm is that it does not need heating, so it has the advantages of high sensitivity, fast response, small power consumption, long life and so on, and has a wider application prospect. In the actual detection, the above two should be combined. The detection personnel can use the lighter air release test method to check whether the alarm can achieve the gas leakage monitoring. The test should be carried out many times.
3. The installation environment of the detector should ensure that the detector can work stably and reliably, and there must be certain requirements for its installation environment. During the installation, appropriate methods must be adopted to avoid and eliminate the interference factors generated by the environment.
(1) No interference, avoid to install in the humid place or the place where oil smoke and dust are concentrated, spray volatile chemicals such as paint, alcohol, etc., to avoid false alarm.
(2) Wall mounted installation is adopted. Before installation, the specific gravity of combustible gas and air shall be determined first, and the alarm shall be installed at a proper position within 1.5m from the air source radius. Gas lighter than air shall be installed 30cm away from the ceiling; gas heavier than air shall be installed 30cm away from the floor. The height of the interior space of family buildings is generally 2.6m. Artificial gas is lighter than air and floats high; natural gas is lighter than air and floats high; liquefied petroleum gas is heavier than air and deposits low.
Shenzhen Lingbao Electronic Co., Ltd