According to the principle of Faraday electromagnetic induction, a pair of detection electrodes are installed on the tube wall perpendicular to the axis of the measuring tube and the magnetic line of force. When the conductive liquid moves along the axis of the measuring tube, the conductive liquid cuts the magnetic line of force to generate an induced electric potential. This induced electric potential consists of two The detection electrode detects that the value is proportional to the flow rate, and its value is:

　　E=KBVD

　　 In the formula:

　　E-induced electric potential;

　　K-coefficient related to magnetic field distribution and axial length;

　　B－Magnetic induction intensity;

　　V－The average flow velocity of conductive liquid;

　　D－electrode distance; (measuring tube inner diameter)

　　 The sensor uses the induced electric potential E as a flow signal, and transmits it to the converter. After a series of digital processing by amplifying, transforming and filtering, the instantaneous flow and cumulative flow are displayed by a dot matrix liquid crystal with backlight. The converter has 4-20mA output, alarm output and frequency output, and is equipped with communication interfaces such as RS-485, and supports HART and MODBUS protocols.

■ Basic skills

Low frequency square wave excitation, excitation frequency: 1/10 power frequency, 1/16 power frequency, 1/25 power frequency; high frequency square wave excitation, excitation frequency: 1/2 power frequency (for slurry measurement) (optional) ; Excitation current can be selected as 125mA, 187.5mA, 250mA;

Empty tube measurement function without additional electrodes, continuous measurement, fixed value alarm; flow rate measurement range: 0.1 --- 15 m/s, flow rate resolution: 0.5 mm/s; AC high-frequency switching power supply, voltage application range: 85VAC- - 250VAC; DC 24V switching power supply, voltage scope: 16VDC --- 36VDC; network function: MODBUS, HART (optional);

　　Chinese and English display mode, (other languages can be customized);

　　 There are three totalizer totals inside, which can be recorded separately: forward total, reverse total, and difference total.

■ Special function

Power-down time recording function, automatically record the power interruption time of the instrument system, and make up the missing flow; hourly total recording function, record the total flow in hours, suitable for time-sharing measurement system; infrared handheld operation keyboard, remote non All functions of the contact operation converter.