How to remove the drift of electromagnetic flowmeter?

Electromagnetic flowmeter consists of two parts: sensor and converter, and works according to Faraday's law of electromagnetic induction. Electromagnetic flowmeters are widely used in chemical and chemical fiber, food, papermaking, sugar, mining and metallurgy, water supply and drainage, environmental protection, water conservancy and hydraulic engineering, steel, petroleum, pharmaceutical and other industrial fields to measure various acid-base, salt solutions, Mud, ore pulp, paper pulp, coal-water slurry, corn pulp, fiber pulp, grain pulp, lime milk, sewage, cooling raw water, water supply and drainage, brine, hydrogen peroxide, beer, wort, various beverages, black liquor, green liquor, etc. conductive Measurement of volumetric flow of liquid media.

The electromagnetic flowmeter will drift during use. How to remove the drift of the electromagnetic flowmeter? 1. Elimination of differential interference and power frequency interference: Differential interference and power frequency interference signals often exist in signals at the same time. Low-pass filtering in signal processing circuits is often difficult to filter out power frequency interference*. Our company uses synchronous sampling and power frequency compensation technology to suppress power frequency interference caused by mixing in the flow signal potential and power frequency fluctuations, and effectively eliminate differential interference. Synchronous sampling technology, the sampling start time lags behind the excitation signal by 1/4 cycle, and the pulse width is an even multiple of the power frequency cycle. It eliminates differential interference and makes the average power frequency interference in the flow signal potential equal to zero to eliminate power frequency interference. influence; the frequency fluctuation compensation of the power frequency power supply ensures that the excitation power supply and sampling pulses can be adjusted synchronously during the dynamic fluctuation of frequency, truly realizing synchronous sampling technology and synchronous excitation technology, synchronous A/D conversion, and reducing differential interference and power frequency Effects of interference. 2. Zero drift elimination: The so-called zero drift means that when the input signal of the sensor is zero, the output of the amplifier is not zero. The zero-point drift signal will be transmitted between various levels of amplified circuits. After multi-stage amplification, it will become a larger signal at the output end. Since the useful signal output by the sensor is weak, the zero-point drift may drown out the useful signal, making the circuit unable to operate. Works normally. Therefore, in order to suppress zero point drift, the differential circuit input of three operational amplifiers is used to collect weak signals with large internal resistance to suppress the introduction of common mode signals. A DC-blocking capacitor is used after the first-level amplifier circuit to filter out the zero-point drift of the baseline and prevent the DC signal from being too large and exceeding the input range of the A/D conversion. 3. Other measures to remove interference: For the orthogonal interference caused by the "transformer effect" of the electromagnetic flowmeter sensor, the "transmitter zeroing method" is used to eliminate it. In terms of software design, digital filtering technology, power-down protection technology, and software instruction redundancy measures are used to effectively improve the reliability of the input microprocessor numbers.

The above are several methods we have summarized to remove drift. If you have better methods when using electromagnetic flowmeters, please share them with us. We are very grateful for your cooperation.