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Hi, it’s still the industrial control expert from Aixue* today. Summer is approaching, and it is a season with frequent thunderstorms. In such weather conditions, lightning strikes pose the biggest safety risk when using electromagnetic flowmeters. The little manager would like to remind all users of electromagnetic flowmeters to take proper lightning protection measures for these devices during the summer. An electromagnetic flowmeter is an electromagnetic induction-type flow measuring instrument. It works by using a converter to supply a stable excitation current to the excitation coil of the electromagnetic flow sensor; the pre-amplifier then amplifies the electromotive force generated by the sensor and converts it into a standard current signal or frequency signal, thereby facilitating the display, control, and adjustment of flow rates. To ensure proper lightning protection for electromagnetic flowmeters, it is necessary to ensure that the sensors at both ends of the flowmeter are grounded during its installation. Only with proper grounding can an electromagnetic flowmeter provide accurate measurements. Some users believe that in an environment free from such interference, not grounding the device does not affect the flow meter’s ability to provide accurate measurements. However, once the environment changes, it can prevent the flow meter from functioning accurately and stably. Therefore, it is best to ensure proper grounding of the sensors during installation, in order to create a favorable working environment for the electromagnetic flow meter. Secondly, it is necessary to ensure that the length of the signal cable between the converter and the sensor of the electromagnetic flowmeter does not exceed 50 M, and the signal cable must be covered with a galvanized tube. If the galvanized pipe is in the air, it must be reliably grounded using a wire, with the grounding resistance being less than 10. If the power supply used is 220V single-phase alternating current, an air switch can be installed inside the control box; the lightning arrester and the air switch are connected in parallel, and a three-phase socket is connected to the wires coming out of the air switch. The length of the lightning arrester grounding wire must not exceed 1 meter; it should be a multi-strand copper-core insulated wire with a cross-sectional area of more than 6 mm². If there is no ground grid in the vicinity, a simple ground grid should be created near the arrester. The method is as follows: Use three flat bars or angle irons, each 1.5 meters long, and drive them into the ground in a triangular arrangement. Weld the three bars together using flat bars, weld a bolt at one of the corners, and then connect the arrester’s grounding wire to it. This applies to 220VAC arrester grounding wires and panel installations at ground level. To ensure the measurement accuracy of electromagnetic flowmeters, it is necessary to pay attention to these matters not only during thunderstorm weather, but also from the initial stage of installation and use; only in this way can potential problems be prevented. That’s all for the little tips in this issue. Aren’t they simple and useful? The little assistant will continue to guide you through various tips related to industrial control; be sure to follow me.