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How to calibrate the square wave signal on the circuit board of a pulse-output vortex flow meter: In the case of no flow signal, when an oscilloscope (or frequency counter) shows that no pulse signal is being generated between terminals TP3-N1-2 on the amplification board, the zero potentiometer W4 can be adjusted to ensure that the output current of the sensor is 4 mA DC. When a full-scale flow pulse signal is applied (between any one of the input terminals of the amplifier board and terminal N1-2), a 1000Hz pulse signal should be output between terminals TP4 and N1-2. The output current of the sensor can be set to 20mA DC by adjusting the W3 range potentiometer; when changing the range, it is necessary to reset coefficients KB and J. When the actual flow rate is below the sensor’s lower limit flow rate, the signal waveform output between terminals TP1-N1-2 on the amplification board, as detected by an oscilloscope, should be approximately linear, with a maximum noise level of ≤100 mVpp. By adjusting the W1 gain potentiometer, it is possible to achieve a noise level of 0mVpp＜noise level≤100mVpp when there is no flow. When the actual flow rate is greater than the sensor’s lower limit, the signal output between terminals TP3-N1-2, as detected by an oscilloscope, should be a continuous pulse square wave. If the signal is discontinuous or absent, a continuous pulse square wave signal can be generated by adjusting the W2 sensitivity potentiometer. When there is no flow or the flow is below the minimum level, and an intermittent square wave signal is generated, this is usually caused by vibration interference; adjusting W2 can ensure that no signal is output. The amplifier board has two toggle damping switches that allow for adjusting the damping time of the output signal, thereby reducing fluctuations in the output signal and stabilizing the output current. Do vortex flowmeters output pulse signals and current signals? Which of these two products has a better performance? The one that’s cheap? After being tuned and calibrated before leaving the factory, the flow coefficient K of the vortex flow meter is indicated on its nameplate. Its physical meaning: at 1 atmosphere and 20°C, the number of pulses generated per liter of fluid as it passes through the sensor (1/L). When installing the sensor, the flow coefficient K must be converted into the instrument coefficient Kt based on the operating conditions and the unit of measurement required, and this value should then be set in the instrument or associated equipment where the instrument coefficient needs to be specified. How to calibrate the square wave signal on the circuit board of a pulse-output vortex flow meter: The circuit part of a pulse-type vortex flow meter consists of an amplification board; by adjusting the sensitivity of this amplification board, it is possible to suppress vibrations and other disturbances, thereby preventing erroneous signal triggers in situations with strong vibrations and ensuring accurate measurement. The sensitivity adjustment potentiometer W2 is set to the appropriate position at the time of manufacture. The purpose of on-site adjustment is to adapt the instrument to the working conditions so that it operates at its optimal level, enabling the sensor to generate regular vortex street signals with minimal electrical and mechanical interference noise under the operating conditions. The intensity of the vortex street signal (signal amplitude) is appropriate, the pulse signals in the circuit are connected evenly, and there are no occurrences of missing signals or multiple trigger signals. The standard for meeting technical requirement a is that the signal waveform observed at the amplifier detection point TP1 is a relatively regular sine wave with only minor noise signals superimposed on it. The signal frequency is stable and changes with flow rate. If the TP1 signal is abnormal, electrical interference should be eliminated by improving grounding, the impact of mechanical vibration noise should be reduced, or the signal quality should be improved by correcting issues such as improper pipeline alignment or incorrect placement of flange gaskets. How to calibrate the square wave signal on the circuit board of a pulse-output vortex flow meter: To ensure that the output pulse signals are uniform and continuous, with no occurrences of multiple triggers or accidental activations, a dual-trace oscilloscope can be used to observe the waveforms of TP2 and TP3 simultaneously; the gain potentiometer W1 and the trigger sensitivity potentiometer W2 can then be adjusted in coordination to achieve this goal. Adjustments should be made first with no flow of fluid. Open the sensor’s front cover and use an oscilloscope to observe the TP3 waveform; if a square wave signal is present when there is no flow, rotate the potentiometer W2 counterclockwise to reduce sensitivity until the pulses disappear. When the vibration at the site is low and the fluid flow rate is very low, if the sensitivity is set too low, there may be no pulse square waves even when there is flow. In such cases, with the pipe flow at the lower limit of measurement, rotate W2 clockwise to increase the sensitivity until normal pulse output is obtained. Therefore, both of the above situations should be taken into account to adjust the position of W2 so that no pulse is generated when there is no flow, while a normal pulse is generated at the lower limit flow rate for measurement.