First, the rotor flowmeter measurement error is large: Hydraulic Pump,Pump Station Valve Block,Hydraulic Valve Assembly Block,Hydraulic Gear Oil Pump Huai'an Aide Hydraulic Machinery Co.Ltd , https://www.aidehydraulic.com
1. The gas medium is affected by temperature and pressure. It is recommended to use temperature and pressure compensation to obtain the true flow rate.
2. Due to long-term use and pipeline vibration and other factors, the floating magnetic flowmeter sensing magnetic steel, pointer, counterweight, rotating magnetic steel and other moving parts are loose, resulting in large errors. Solution: You can verify by hand pushing the pointer first. First press the pointer to the RP position to see if the output is 4mA, whether the flow display is 0%, and then verify according to the scale. If the discrepancies are found, the parts can be adjusted. Generally require professional adjustment, otherwise it will cause the position to be lost, need to return to the manufacturer for correction.
3. Installation does not meet the requirements: for the vertical installation of the rotor flowmeter to maintain vertical, the inclination angle is not more than 20 degrees; for horizontal installation of the rotameter to maintain horizontal, the inclination angle is not more than 20 degrees; there must be no ferromagnetic objects in the 100mm space around the rotameter . Install the position away from the valve reducer, pump outlet, process line turn, etc. To maintain the requirements of the 250mm straight pipe section after the first 5D.
4. The large change in density of the liquid medium is also a cause of large errors. Since the instrument is converted according to the density given by the user before the calibration, the flow is converted into the flow rate of the water under the calibration state. Therefore, if the density of the medium changes greatly, the measurement will cause a large error. The solution can bring the density of the medium after the change into the formula, convert it into the error correction coefficient, and then multiply the flow measured by the flow meter by the coefficient to convert it into the real flow.
Second, the rotor flowmeter pointer jitter:
1. Slight pointer jitter: generally caused by media fluctuations. It can be overcome by increasing the damping.
2. Moderate pointer jitter: generally due to media flow conditions. Gases are generally caused by unstable media operating pressures. A steady or steady flow device can be used to overcome or increase the rotor meter air damping.
3. Violent pointer jitter: mainly due to medium pulsation, unstable air pressure or the pressure, temperature and flow of the gas operating state given by the user are inconsistent with the actual state of the rotor flowmeter, and there is a large difference in the rotor flowmeter over-range.
Third, the rotor flow meter pointer stops at a certain position:
The main reason is that the rotor of the rotameter is stuck. Generally, when the rotameter is used, the valve is opened too fast, so that the rotor quickly impacts the stopper upward, causing the stopper to deform and the rotor to be stuck. However, it is not excluded that the rotor is stuck due to the difference between the rotor guide rod and the stop ring. During the treatment, the instrument can be removed, the deformed stopper can be removed and shaped, and checked whether it is concentric with the guide rod. If the heart is not correct, the rotor can be installed and the rotor can be pushed by hand to feel the smooth and unobstructed card of the rotor. Yes, in addition, when the rotameter is installed, it must be installed vertically or horizontally, and it cannot be tilted. Otherwise, it will easily cause the card table and bring errors to the measurement.