Once the sensor has detected the gas, it can transmit the signal in several ways:
- each sensor has a dry contact, which is closed during operation. The signal from the dry contact can be output to a light bulb, button, or sounder alarm outside the electrical installation. In this case, the light or sound indicator keeps until the alarm is reset.
- the sensors can be connected to the monitoring control unit (MCU Thermosensor) via radio channel or twisted pair (Modbus RS-485). In this case, an audio alert appears on the control panel, the alarm light lights up, and the display shows information about which sensor was triggered and at what time. The alarm is reset manually. Some control panel models can transmit a message about sensor activation to a mobile phone or related systems.
- sensors can be directly integrated into an existing dispatching system via Modbus Protocol or radio channel. In this case when triggered the sensor only reports its address.
Receiving a signal from the gas sensor means that there is an overheating, but it is not a fire alarm. The alarm message is a reason to pay attention and take measures to find and eliminate the cause of overheating
After receiving a signal that the sensor is triggered, you need to open the installation and find out which sticker was heating and released gas. To determine the specific location of overheating, each sticker has indicator points that irreversibly blacken when the temperature reaches 50-60-70-80-90оС. The presence of an indicator scale on the labels allows not only to identify the area where there was an overheating above the gas release temperature (the highest permissible heating temperature), but also informs about warning heats (50-60-70-80-90оC) during the operation of electrical equipment.
After identifying and eliminating the cause of overheating the sticker should be replaced and after that the system will continue to work.
The main know-how of the Thermosensor system is the special material from which the sticker is made. It is a composite polymer consisting of micropores filled with a special liquefied gas. The gas is safe for humans and the environment, has no smell and does not burn. One cubic sm of microporous sticker material contains more than a billion pores containing 150 ml of gas. This amount is sufficient for a confident sensor response in a volume of more than 1 m3!
Due to this structure the sticker is not sensitive to physical damage. A break or incision destroys the pores only in the place of the cut. Other pores remain sealed and retain the gas until heating.
Different pore diameters and wall thicknesses provide another important property of the sticker: each pore has its own opening temperature, which can exceed the operating temperature by 30-50оC. Thus, when reheating to a temperature 5-10 degrees above the initial heating, the sticker will release another portion of gas sufficient to re-activate the sensor.
The gas inside the pores – a mixture of freon 365 with fire-extinguishing freon 227 - is selected according to following properties:
- no negative impact on human health, the ozone layer and the environment. The simultaneous release of gas from all stickers in the electrical installation will not lead to the formation of any dangerous environment for personnel.
- gas does not ignite, has a higher breakdown voltage compared to air.
- gas is exotic and under normal conditions can not” just" be in the atmosphere.
The gas sensor is made on the basis of a semiconductor that has a special coating. The presence of a signal gas in the analyzed air leads to a change in the resistance of the sensor element, which is fixed by the controller.