Ultrasonic water flow meter adopts the new electronic technology of microprocessor and ultrasonic echo recognition, which has high accuracy and good reliability. It has interfaces of RS232, 4~20 mA, RS-485 and pulse output, which is suitable for all TV transmission requirements. The reception of energy and signals is carried out through an anti-interference structure, which can work normally under harsh conditions.
Ultrasonic water flow meter selection
Common Ultrasonic water flow meter mainly portable ultrasonic flow meter, handheld ultrasonic flow meter and fixed ultrasonic flow meter, the three flow meter features are compared as follows:
(1) portable ultrasonic flow meter for non-contact measurement, small size, easy to carry. Suitable for on-site measurement of various sizes of pipeline sound-conducting medium. Measuring medium including water, industrial sewage, acid and alkali liquids, various oils and other liquids that can conduct sound waves. Measurement of the flow rate range of (0 ~ ± 30) m / s, measurement accuracy level better than 1%.
(2) Handheld ultrasonic flowmeter, small size, light weight, easy to carry, flexible operation, automatic data storage, full Chinese display. Measuring media including water, seawater, industrial sewage, alcohol, acid reduction fluid, various oils and other uniform, single, stable liquid. The flow rate range is (0.01 ~ ± 32) m / s, the measurement accuracy level is better than 1%.
(3) Fixed ultrasonic flowmeter, compact, sturdy, internationally advanced die-casting aluminum chassis. Measuring media including water, seawater, industrial sewage, acid and alkali liquids, various oils and other liquids that can conduct sound waves. The flow rate range is (0 ~ ± 30) m / s, the measurement accuracy level is better than 1%.
Bio-chemical enterprise production system contains a small amount of impurities in the circulating water, the comprehensive factors to consider, the pipeline circulating water flow is appropriate to use portable ultrasonic flowmeter for measurement.
What affects the accuracy of ultrasonic water flow meter measurements?
Noise
In the design and installation process, the influence of noise must be concerned. In the actual working process, the flow rate, temperature, pressure and other parameter factors will also change, the flow meter is used in the process of noise interference is very obvious, after the emergence of the meter will appear obvious transmission errors, and will be issued to indicate. In a variety of industrial production, the noise will be generated with the pipeline, valves, various equipment components, a variety of pipe walls to spread, the noise formed by the interference will lead to the measurement of equipment can not work properly.
Dust accumulation
Impurities will accumulate on the surface of the pipeline, and even block the probe, thus causing some deviation in the detection data. If there is a large number of impurities attached to the probe, it will reduce the transmission efficiency of ultrasound, which in turn affects the sensitivity of the probe. If the equipment on the accumulation of ash, flow meter measurement will have a large deviation, if the accumulation of ash is serious will directly affect the accuracy of measurement.
Fluid velocity
ultrasonic flowmeter in theory is a uniform distribution of fluids in the pipeline, but in practice, there is no uniform distribution of flow rate, the distribution of fluids there will be errors and affect the accuracy of measurement. In addition, the liquid density, fluid velocity, refraction, straight section will affect the measurement of the flow meter.
The solution to the measurement accuracy of ultrasonic water flow meter
Reducing Noise
Noise can have a great impact on the equipment. Before installing the pipeline, one is in accordance with the installation requirements given by the manufacturer of the flow meter, should first consider installing the regulating valve downstream of the ultrasonic flow meter, and ensure that there is as large as possible installation distance. Ensure that the fluid economic flow rate, prohibit over-flow, overload operation. Secondly, in the operation of the flow meter before and after the valve, to slowly switch the valve to avoid violent pressure fluctuations, fundamentally reduce the impact of noise.
Reduction of impurities near pipelines
In the management of water flow monitoring operations, dust should be cleaned in the vicinity of the pipe section and flow meter in a timely manner. After cleaning, if there is corrosion, contact a technician. Judgment based on the problem. For example, when the measurement equipment on the inner wall of the accumulation of dirty substances, the software will show that the equipment acceptance rate and gain parameters are unreasonable, after the emergence of analysis and judgment, it can be dealt with. Usually should reduce the use of large-diameter flowmeter.
Temperature and pressure
Pressure and temperature have a great influence on ultrasonic flow, which directly affects the compression factor and the calculation of the nominal flow. Daily work should pay attention to the following points:First, we should do a good job of pressure change, temperature change regular calibration work, to ensure that the transmitter measurement accuracy within the specified range. The second is to do a good job of measuring the comparison of the measurement data of the branch circuit, the use of a good comparison table on the site, in time to check out the deviation of the transmitter. Third, regular maintenance of measuring instruments, regular zero calibration, replacement of thermal oil and so on. Fourth, do a good job in the field transmitter and station control machine measurement value comparison, to ensure that the communication is reliable and error-free.
