流体正常流动时无显示，总量计数器字数不增加 I. 1. Failure phenomenon: No display when the fluid flow of the turbine flowmeter is normal, the total number of words does not increase
2. Possible causes: a Check the power cable, fuse, function selection switch and signal line for open circuit or poor contact. B Check the display board for poor contact. C Check the detection coil. D Check the internal fault of the sensor. All the inspections in 1-3 have confirmed that the fault is normal or eliminated, but there is still a fault phenomenon, which indicates that the fault is inside the sensor circulation channel. You can check whether the impeller touches the inner wall of the sensor, whether there is foreign matter jamming, and whether the shaft and bearing are jammed. Fracture
3. Solution: a. Use an ohmmeter to troubleshoot the fault. B. Print board failure inspection can be replaced by the "spare version" method. Replace the faulty board and perform a detailed inspection. C. Make a position mark on the sensor body of the sensor coil and unscrew it. Head, use the iron piece to move quickly under the detection head, if the number of counter words does not increase, you should check the coil for disconnection and solder joint desoldering. D Remove foreign objects, and clean or replace damaged parts. The impeller should be free of friction noise. After replacement of bearings and other parts, it should be re-calibrated to obtain a new meter coefficient.
Second, 1. Failure phenomenon: The turbine flowmeter pipeline valve has not been operated to reduce the flow rate, but the flow rate display has gradually decreased. 2. Possible cause a Whether the filter is clogged. If the filter pressure difference increases, it indicates that debris is blocked. B Flow The valve spool on the sensor pipe section is loose, and the valve opening degree is automatically reduced. C. The sensor impeller is blocked by debris or the bearing clearance enters the foreign body, and the resistance increases and slows down. 3. Solution: a. Eliminate the filter. B. Is the valve handwheel adjusted? Effective judgment, repair or replace after confirming c Remove the sensor to clear, and re-check if necessary
Three, 1. Failure phenomenon: the fluid in the turbine flowmeter pipeline does not flow, the flow display is not zero, or the displayed value is unstable
2. Probable cause a. The shield of the transmission line is poorly grounded, and external interference signals are mixed into the input terminal of the display. B. The pipe vibrates, and the impeller shakes with it, generating false signals. C. The shut-off valve is not tightly leaked. Interference between circuit boards or the deterioration of electronic components 3. Solution a. Check the shielding layer and the terminals of the indicator are well grounded b. Strengthen the pipeline or install brackets before and after the sensor to prevent vibration c. Overhaul or replace the valve d. ”Or check one by one to determine the source of interference and find the fault point
显示仪示值与经验评估值差异显著2.可能原因a 传感器流通通道内部故障如受流体腐蚀，磨损严重，杂物阻碍使叶轮旋转失常，仪表系数变化叶片受腐蚀或冲击，顶端变形，影响正常切割磁力线，检测线圈输出信号失常，仪表系数变化：流体温度过高或过低，轴与轴承膨胀或收缩，间隙变化过大导致叶轮旋转失常，仪表系数变化。 4. 1. Failure phenomenon: Turbine flowmeter display instrument display value and empirical evaluation value are significantly different. 2. Possible cause a. The internal failure of the sensor's flow channel, such as fluid corrosion, serious wear, debris blocking the impeller rotation, the meter coefficient changes. Corrosion or impact, deformation of the top end, affecting the normal cutting of magnetic field lines, detection of abnormal coil output signals, changes in meter coefficients: fluid temperature is too high or too low, shafts and bearings expand or contract, and excessive gap changes cause impeller rotation abnormalities, and meter coefficients change . b Insufficient back pressure of the sensor, the occurrence of air pockets, which affects the flow of the impeller c. If the reverse flow bypass valve is not closed without a check valve installed, and there is a large flow velocity distribution distortion upstream of the leaked sensor: (such as Caused by the upstream valve not being fully opened) or the pulsating liquid has a large viscosity change due to temperature, etc. d Internal fault of the display e The permanent magnet material element in the detector is demagnetized, and the weakened magnetism to a certain extent will also affect the measured value f sensor The actual flow passed has exceeded the flow range specified by the sensor. 3. The solution ad finds out the cause of the failure, and finds a solution for the specific cause. E. Replace the demagnetizing element. F. Replace the appropriate sensor.
原理：当被测流体流过传感器时，在流体作用下，叶轮受力旋转，其转速与管道平均流速成正比，叶轮的转动周期地改变磁电转换器的磁阻值。 Turbine flowmeter principle: When the measured fluid flows through the sensor, under the action of the fluid, the impeller is forced to rotate, and its speed is proportional to the average flow velocity of the pipeline. The rotation of the impeller periodically changes the magnetic resistance of the magnetoelectric converter. The magnetic flux in the detection coil changes periodically, generating a periodic induced potential, that is, an electric pulse signal, which is amplified by an amplifier and sent to a display instrument for display. Turbine flowmeter pulse output type, suitable for total measurement and computer connection, no zero drift, strong anti-interference ability. The meter coefficient of the turbine sensor is derived from the flow calibration device. It does not ask the internal fluid mechanism of the sensor at all, and treats the sensor as a black box. The conversion coefficient is determined according to the input flow rate and the output frequency pulse signal. It is convenient for practical applications. Large-caliber turbines How many pulses / cubic meter is the meter factor? How many pulses / liter is the meter factor for small-diameter turbine flow meters (such as DN4, DN6). When the turbine flow meter is connected to the PLC or DCS, it only needs to detect a certain flow time. The number of pulses generated can be used to determine the flow rate. For example: if a caliber turbine flowmeter is calibrated to 100O pulses / m3 and the number of pulses detected in a unit time is 6,500, the flow rate in a unit time is 6500/1000 = 6.5m3