working principle:
The FR12B type explosion-proof flow switch is designed based on the L.V.King heat exchange principle. A flow sensor is installed at the front end and two probes are in contact with the medium. One measures the temperature of the medium, the other measures the temperature and is heated. When there is no medium flowing, the temperature of the two probes is the largest. When the medium flows, the temperature difference between the two probes becomes smaller. The temperature difference is only related to the flow velocity of the medium. The larger the flow rate is. The smaller the temperature difference is, the smaller the flow velocity is, the larger the temperature difference is, and the maximum temperature difference is when the flow is not flowing, and is related to the thermal conductivity temperature of the medium itself. When the flow rate is lower or higher than a certain set value, the relay is turned on or off. Output switching signal. The explosion-proof mark of this product is ExdIICT6 Gb, which meets the requirements of GB3836.1 and GB3836.2. Applicable to Zones 1 and 2, Class IIA, IIB, and IIC of explosive hazardous environments. The ignition temperature group is the place where the flammable gas of T1--T6 group or the explosive mixture formed by steam and air.
Note: When installing or using this product, it is strictly forbidden to open the cover and operate with power.
Features:
1. No mechanical movable parts, corrosion-resistant, stable and reliable, long service life, no special maintenance for long-term operation.
2. The probe probe and the signal processing circuit are designed in one piece, and the installation and debugging are simple and convenient.
3. Built-in temperature compensation circuit, the error caused by the medium and ambient temperature on the flow rate of the fluid is minimized.
4. Preferred new circuit, low heat generation and high reliability.
5. This product has built-in relays and only outputs switching signals.