1.Select the corresponding pump according to the pipe diameter and flow rate for the verification test.
2. If the system adopts compressed air power, turn on the air compressor to reach the air source pressure required by the system to ensure the rapid switching of the commutator and the normal operation of the clamp meter.
3. After the electromagnetic flowmeter is correctly installed and connected, it should be energized and preheated for about 30 minutes in accordance with the requirements of the verification regulations.
4. If a high-level tank water source is used, check whether the overflow signal of the stabilized water tower appears. Before the formal test, according to the requirements of the verification regulations, the verification medium should be circulated in the pipeline system for a certain period of time. At the same time, check whether there is any leakage in the sealing parts of the pipeline.
5. Before starting the formal verification, the verification medium should be filled with the tested electromagnetic flowmeter sensor, and then the downstream valve should be closed for zero adjustments.
6. At the beginning of the verification, the valve at the front of the pipeline should be opened first, and the valve behind the flow meter under test should be slowly opened to adjust the flow rate at the verification point.
7. During the calibration of the electromagnetic flowmeter, the flow stability of each flow point should be within the 1% to the 2%-flow method, while the total amount of law can be within 5%. When the verification process of a flow point is completed, the temperature change of the verification medium should not exceed 1°C, and when the entire verification process is completed, it should not exceed 5°C. The pressure downstream of the tested electromagnetic flowmeter should be high enough to ensure no flashing and cavitation in the flow pipeline (especially in the reduced diameter);
8. After each test, close the valve at the front end of the test pipeline, and then stop the pump. At the same time, the remaining verification medium in the test pipeline must be emptied, and finally, the control system and the air compressor must be closed.