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I. Overview of external stick-on ultrasonic level switch:
The external stick-on ultrasonic level switch is a new type of liquid level monitoring and fixed-point level measurement and alarm device for the liquid in the container. It is mainly used to monitor the liquid level of storage tanks, to realize the upper and lower limit alarms or to monitor whether the medium exists in the pipeline (dry state protection), and can be widely used in the liquid level process control in petrochemical, chemical, oil depot, petroleum, electric power, liquid storage and transportation, pharmaceutical and other industries. It has significant advantages in the field of fixed-point liquid level measurement and alarm for pressure vessels, hazardous chemical liquids, flammable and explosive liquids, and so on.
II. The working principle of external ultrasonic level switch
The high-frequency ultrasonic pulse generated by the sensor (probe) of the liquid level switch can pass through the vessel wall, and this pulse will propagate in the vessel wall and liquid, and will be reflected back. Through the detection and calculation of this reflection characteristic, it can be judged whether there is liquid in the container at the monitoring point. At the same time, the level switch can output relay signals to the back stage electrical appliances or other equipment, so as to realize the monitoring or control of the liquid level.
III. Features of external ultrasonic level switch
Installation outside the tank, no open hole, no fire, no damage to the tank, can be installed without stopping production and maintenance;
Non-insertion measurement, with the media pressure, specific gravity, corrosive or not have nothing to do with, adapt to a wide range;
External measurement, no interference with the medium in the tank or device, no pollution, no leakage, no corrosion;
Applicable to petrochemical atmospheric pressure or high pressure tanks and devices, strict health requirements of food tanks, pharmaceutical tanks and strong corrosive tanks, is an environmentally friendly instrument;
Problems to pay attention to the maintenance of external level meters:
1. The liquid level measuring head is a very sensitive part and it must be handled with care to avoid damage. Do not remove the installed level measuring head without the presence of factory designated maintenance personnel. Instrumentation can not work stably and normally, usually due to the level measuring head is not properly installed caused. Therefore, the vessel wall where the measuring head is to be installed must be smooth and level.
2. E-0, E-1 code appears, indicating that the instrument self-test did not pass, restart. 3.
3. E-2 code appears, it means that the parameter setting is wrong, and the parameters should be reset.
4. Frequent automatic reset after power-on indicates that the circuit board or level measuring head is damaged, and the parts should be replaced.
5. the meter keeps displaying a small moving bar after power on or reset, it means the meter does not measure the level signal or the signal is too weak, it may be bad contact with the outer wall of the container, bad contact with the cable, etc.
