With the need for the development of industrial automation, the instrumentation industry has developed rapidly. However, most of these intelligent instruments, which use a large number of micro-electric devices, have low insulation strength and primary problems with surge resistance. Therefore, the lightning protection of smart instruments and meters is very important, especially during the thunderstorm season to avoid huge losses.


Guided wave radar level gauge instrument lightning protection, we must start unilaterally, including internal system lightning protection and internal system lightning protection, generally mainly by participating in lightning protection devices. Specifically, the following methods can be used to develop lightning protection.

1. Lightning protection starts with grounding systems. The casing of the radar level gauge is very similar to the control cabinet, monopoly, power cabinet, etc. The casings are all adjacent to each other with flat steel. The instrument task power supply, such as the 24V negative terminal, is connected to the instrument signal ground, and the input and output signal ground of the totalizer to form an equipotential. Intrinsically safe grounds, safety barriers, barriers, safety devices and other grounding should also consider whether the instrument signal reference point can be equipotential when it is adjacent.

2. The lightning protection of the power supply of smart instruments and meters cannot be ignored. Install anti-surge systems for smart instruments and meters to ensure that the instrument does not exceed the withstand voltage limit. The surge injection device is required to send the overload current into the earth when a thunderstorm is induced by a thunder surge.

3. To equip smart instruments with trust number channel surge generators, not only to ensure that the dynamic transmission is accurate, stubborn, and agile, but also to discharge the piezoelectric surge to the ground during thunderstorms to ensure the safety of signal transmission.

4. Regularly develop, search and repair the power supply system grounding, bus bars, grounding bodies, surge devices, power lightning protection grids of smart instruments and meters, and change them in time.

Precautions for selection

The correct selection of the radar level gauge can ensure the better use of the radar level gauge. What kind of radar level gauge should be selected according to the physical and chemical properties of the fluid medium to be measured? Make the diameter, flow range, lining material, electrode material and output current of the radar level gauge suitable for the test The nature of the fluid and the requirements for flow measurement.

1. Precise function inspection

Accuracy grade and function Choose the instrument accuracy grade according to the measurement requirements and use occasions, so as to be economical and cost-effective. For example, for trade settlement, product handover and energy metering, you should choose a higher accuracy level, such as 1.0, 0.5, or higher; for process control, choose different accuracy levels according to the control requirements; some only It is to check the process flow and do not need to do precise control and measurement. You can choose a lower accuracy level, such as 1.5, 2.5, or even 4.0. At this time, you can choose a cheap plug-in radar level meter.

2. Measurable medium

When measuring medium flow rate, instrument range and caliber, when measuring general medium, the full-scale flow rate of the radar level gauge can be selected within the range of 0.5-12m/s to measure the medium flow rate, and the range is relatively wide. The instrument specification (caliber) selected is not necessarily the same as the process pipeline. It should be determined whether the measurement flow range is within the flow rate range, that is, when the flow rate of the pipeline is too low to meet the requirements of the flow meter or when the measurement accuracy cannot be guaranteed at this flow rate, It is necessary to reduce the diameter of the meter to increase the flow velocity in the pipe and obtain satisfactory measurement results.