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The Type Of Electromagnetic Flowmeter

Jul 25, 2017

Electromagnetic  flowmeter can be classified in a variety of categories, according to  the classification of excitation, according to the composition of  sensors and converters classification, according to the classification  of the connection according to the sensor and pipe connection method can  also be classified according to use, this article mainly introduced by  excitation classification The

1) DC excitation type. This kind of electromagnetic flowmeter is very small, only used to  measure the flow of liquid metal, such as mercury at room temperature  and high temperature liquid sodium, potassium and so on.

2) AC frequency excitation type. Early  electromagnetic flowmeter with 50Hz frequency frequency of commercial  excitation, due to susceptible to electromagnetic interference and zero  drift and other reasons, has been gradually replaced by low-frequency  rectangular excitation. However,  in the measurement of mud, slurry and other liquid-solid two-phase  flow, the low-frequency rectangular wave excitation method can not  overcome the solid rubbed the electrode surface spikes, and frequency AC  excitation instrument does not exist this shortcoming, so at home and  abroad There are some electromagnetic flowmeter still use AC excitation mode.

3) low frequency rectangular wave excitation type. For  low frequency rectangular wave excitation mode power consumption is  small, zero stability, is the main electromagnetic flow meter excitation  method. The waveform has "positive - negative" binary value and "positive - zero - negative - zero" three - value two. Some three smooth electromagnetic flowmeter excitation frequency can  be set by the user, the general small diameter meter with a higher  frequency, large diameter meter with a lower frequency.

4) Dual frequency excitation type. The current of the excitation current is to super high frequency  rectangular wave on the low frequency rectangular wave, mainly to  overcome the existence of slurry noise and flow noise of the binary  rectangle wave excitation, and improve the stability and response  characteristics of the instrument.