Electromagnetic flowmeter selection and installation form

Case introduction

Key points for selecting electromagnetic flowmeter

1. The first thing to make clear is to choose a pipeline type geomagnetic flowmeter or an insertion type electromagnetic flowmeter.

2. Generally, an on-site non-display electromagnetic flowmeter is used to output a 4-20mA (or 0-10mA) current signal on the secondary instrument in the control room, which can display the flow rate and total amount.

3. If you emphasize observing the internal flow of the pipeline during on-site operations, you can choose to display the electromagnetic flowmeter on site.

4. When environmental requirements or measurement accuracy requirements are high, safety voltage intelligent electromagnetic flowmeters can be selected.

Select the installation form

1. Integral type: The sensing part and conversion part of the flow meter are assembled together, which has the advantage of easy installation.

2. Separation: The sensing part of the flow meter is installed on the pipe under test, and the conversion part is installed in a room that is convenient for operation. Suitable for occasions with poor on-site environment (but the separation length should be less than 30m).

Enterprises can conduct a comprehensive inspection of the electromagnetic flowmeter every year. The inspection content includes: appearance inspection, converter characteristic test, measurement value calibration, voltage measurement of each component, insulation resistance measurement, confirmation circuit, etc. When checking and adjusting the instrument, it is very important to adjust the zero due to zero drift ("online zeroing" the measured medium must stop flowing, which is not easy in practice). Therefore, online inspection usually ignores the check of sensor operation and only implements the calibration of the converter so that the online inspection results can be compared with historical data to determine whether the instrument continues to be used. Repair or update, whether the sensor is updated depends on the measured excitation coil insulation The degree of deterioration of the resistance.