Electromagnetic flowmeter installation method

The flowmeter is an indispensable instrument for measuring the flow of liquid and gas. The correct installation method is very important for the flowmeter.

The measurement principle of the electromagnetic flowmeter does not depend on the characteristics of the flow. If there is a certain turbulent flow and vortex in the pipeline, it has nothing to do with the measurement.

A. There should be no large vibration source at the installation site, and reinforcement measures should be taken to stabilize the pipeline near the flowmeter; 

B. It cannot be installed near equipment that generates large magnetic fields such as large transformers, motors, pumps, etc., so as to avoid interference from electromagnetic fields;

C. When the sensor is connected to the pipeline, it should be ensured that the pipeline is full, and it is best to install it vertically;

D.The transmitter shell, shielded cable, measuring body and pipes at both ends must be grounded, the grounding electrode should be set separately, the grounding resistance should be less than 10Ω, and cannot be connected to the electrical or public grounding network;

E. It is required to have a straight pipe section with the diameter of the first 5 times and the latter 3 times the pipe diameter. 

If there is a steady eddy current in the measurement area, it will affect the stability and accuracy of the measurement. At this time, you can increase the length of the front and rear straight pipe sections, use a flow stabilizer or reduce the cross section of the measurement point to stabilize the flow velocity distribution.

The flowmeter can be installed horizontally and vertically, but the influence of deposits and air bubbles on the measuring electrode should be avoided, and the electrode axis should be kept horizontal. When installed vertically, the fluid should flow from bottom to top.

The sensor cannot be installed in the highest position of the pipeline, and it is easy to accumulate air bubbles.

When the flow sensor is measuring, the pipeline is filled with the fluid to be measured, and the non-full pipeline state cannot occur. 

If the pipeline is not full or the outlet is empty, the sensor should be installed on a siphon.

The conventional straight pipe section requirements of electromagnetic flowmeters are 10D in the front and 5D in the back. There are different requirements in the case of elbows and valves.

Reasons for the grounding of the electromagnetic flowmeter: 

The measuring electrode in the electromagnetic flowmeter is in a direct current or alternating current electric field, if its environment cannot be effectively shielded in a non-interference condition, it will seriously interfere with the measurement. Whether the sensor shell is grounded or not is directly related to the accuracy and stability of the measurement. The grounding wire must not transmit any interference voltage. Therefore, the electromagnetic flowmeter requires a very reliable grounding and grounding shielding. Otherwise, interference current will be generated. However, the advantages of grounding the electromagnetic flowmeter: If the pipeline connecting the sewage flowmeter is insulating (relative to the measured medium), a grounding ring should be used, and its material should be selected according to the corrosiveness of the measured medium. If it is a PTFE sensor, in order to protect the PTFE flanging from damage, a grounding ring should be selected.