The liquid flow rate of the electromagnetic flowmeter at full-scale flow can be selected within 0.5-10m/s, and the range is relatively wide. The upper limit flow rate is not limited in principle due to the small resistance loss of the instrument. However, it is generally recommended not to exceed 5m/s, unless the material in the village can withstand the erosion of the liquid flow. In practical applications, it rarely exceeds 7m/s, and it is more than 10m/s. It’s even rarer. The lower limit of the flow velocity of the full-scale flow is generally 1m/s, and some models are 0.5m/s.
The caliber of the selected instrument is not necessarily the same as the pipe diameter, it should be determined by the flow rate. For liquids with low viscosity such as process industrial water, the pipe flow rate should be set at an economic flow rate of 1.5-3m/s.
The electromagnetic flowmeter is used in such a pipe system, as long as the diameter of the flow sensor is the same as the pipe light. In some newly-built projects, in the initial stage of low-load operation, the flow rate is low or the full-scale flow rate is less than 0.5m/s. From the perspective of measurement accuracy, the gauge diameter should be changed to be smaller than the pipe diameter. It will be economically cost-effective to refit after the increase in traffic in the future.
For fluids that are easy to adhere to, deposit, scale, and other substances, the flow rate should not be less than 2m/s, preferably 3-4m/s or more, to play the role of self-cleaning and prevent adhesion and deposition. It is used for washing bodies with strong abrasiveness such as mineral pulp. The usual flow velocity should be lower than 2~3m/s to reduce the wear of the lining and the electrode.
Measure the low-conductivity liquid close to the threshold, and choose a lower flow rate (0.5 ~ 1m/s) as much as possible. As the flow rate increases, the flow noise will increase, resulting in output shaking.
The range of the electromagnetic flowmeter is relatively large, usually not less than 20, and the meter with automatic range switching function can exceed 50-100.
It should be broken down into two indicators, the upper limit range (rangeability) and the range degree (turn down).
The size of the final product available in China ranges from 10 to 300mm. Compared with most other principle flow meters (such as volumetric, turbine, pot street, and Coriolis quality), the application of large-caliber meters occupies a larger proportion. Although the actual application is still mostly small and medium calibers, this can be seen from the caliber statistics of nearly 10,000 meters shipped by a certain company. 37%, 45%, 15% and 3%.