The factors influencing electromagnetic flowmeter measurement precision
Electromagnetic flowmeter is a kind of production according to the principle of electromagnetic induction measuring pipeline sprocket dielectric volume flow meter, electromagnetic flow meter in the measurement of medium flow problems, there are some factors will affect the precision during do to list in this paper.
1, if the medium to be measured in contain metal, electrode are prone to short-circuit phenomenon of electromagnetic flowmeter, electromagnetic flowmeter measurement at this time of little value or zero. This is often not the case in the process of production, at ordinary times when measuring high viscosity medium, because of the easy adhesion and deposition wall, fluid near the electrodes, reduce the conductivity of the medium, the electrode signal can't work normally, electrode short circuit. If not conductive layer when the sediment, will cause the electrode open circuit, electromagnetic flowmeter can't work normally, if the metal deposits, its conductivity is greater than the liquid conductivity, the actual flow values are higher than the measured flow value. If sediment is scale, the conductivity is higher than the measured medium sediment, the measurement value is less than the actual flow rate value.
2, the electromagnetic flowmeter measurement of liquid or dirt opportunity more than other flowmeters, inner surface adhesion layer influence the precision of probability will also be higher. If the adhesive layer conductivity and electrical conductivity measured medium, flow meter is normal output signal, just change the circulation area, influence the accuracy of measurement error contact fault; If high conductivity adhesive layer, electrode electromotive force will be short circuit; If the insulation adhesive layer, electrode surface bai insulation and disconnect the measurement circuit. After the two cases electromagnetic flowmeter can work normally.
3, the influence of environment change on the electromagnetic flowmeter, because during debugging environment condition is good, electromagnetic flowmeter work normally, at this point is often easy to overlook the installation conditions, in this case, the environmental conditions change, run during the emergence of a new interference sources, is to interfere with the normal work of the electromagnetic flowmeter, electromagnetic flow of the output signal will fluctuate.
4, the lightning effect on electromagnetic flowmeter, high voltage induction lightning circuit transient surge current, the meter instrument damage. Therefore, completes the power circuit control room lightning protection facilities, prevention of lightning electromagnetic flowmeter is very important.
Electromagnetic flowmeter is a play a role of perfection in the industrial production of flow measuring. Its parts no moving parts and it didn't stop flow of parts, so there would be no pressure loss. Electromagnetic flowmeter installation of very convenient also, horizontal, vertical, inclined way have to be able to; High measurement precision, large range; Only with the measured medium pipe lining and electrode were part of the electromagnetic flowmeter contact, material use decay resistance, abrasion resistance and reasonable choice.
Along with the growth of the use of time, the electromagnetic flowmeter aging slowly, will also cause the loss of accuracy, in order to prolong the service life, ensure the accuracy of measurement, do the following:
(1), in order to strengthen the management of the operation of the electromagnetic flowmeter, the remains of a sensor in electromagnetic flowmeter sensor are no drainage pipe, through artificial will separate the ruled out. But due to various reasons, not in time that might not prepared to single precision.
(2),Electromagnetic flowmeter is influenced by environment, electromagnetic flowmeter after installation to the scene debugging good, as far as possible can eliminate or prevent environmental changes produce new interference factors of accuracy of measurement.