To ensure the measurement accuracy of the electromagnetic flowmeter, proper installation is very important.
The transmitter should be installed in a dry and ventilated place indoors. Avoid installation in places where the ambient temperature is too high, should not be subject to strong vibration, try to avoid equipment with strong magnetic fields, such as large motors, transformers, etc. Avoid installation in corrosive gases. The installation location is easy to overhaul. This is the environmental condition to ensure the normal operation of the transmitter.
In order to ensure that the measuring tube of the transmitter is filled with the measured medium, the stacker is preferably installed vertically, and the flow direction is from bottom to top. Especially for liquid-solid two-phase flow, it must be installed vertically. If the site is only allowed to be installed horizontally, it must be ensured that the two electrodes are at the same level.
The transmitter should be equipped with valves and bypass at both ends.
The millivolt AC potential measured by the electrode of the electromagnetic flow transmitter is based on the liquid potential in the transmitter. In order to stabilize the liquid potential and maintain the potential of the transmitter and fluid to ensure stable measurement, the transmitter shell and the metal tube should have good grounding at both ends, and the converter housing should also be grounded. The grounding resistance should not be greater than 10 and cannot be shared with the grounding wire of other electrical equipment. If the transmitter housing is not guaranteed to be in good contact with the metal pipe, connect them with metal wires. Re-reliable grounding.
In order to avoid interference signals, the signal between the transmitter and the converter must be transmitted with shielded wires. It is not allowed to place the signal cable and power cable in parallel in the same cable. The length of the signal cable should generally not exceed 30 m.
Converter installation site should avoid AC and DC strong magnetic field and vibration, ambient temperature is -20 to 50 ° C, does not contain corrosive gases, relative humidity is not more than 80%.
In order to avoid the influence of the flow rate on the relative measurement, the flow regulating valve should be placed downstream of the transmitter. For small-caliber transmitters, since the distance from the center of the electrode to the inlet end of the flowmeter is equivalent to several times the length of the diameter D, the upstream straight pipe may not be specified. However, for a flowmeter with a large diameter, generally there should be a straight pipe section of 5D or more in the upstream, and the downstream pipe section is generally not required.
Working principle and sensor parameters of ultrasonic external clamp flow meter
External clip type ultrasonic flow meter external clip type ultrasonic flow meter series measuring full flow of liquid flow meter, optional explosion-proof and intrinsically safe type, explosion-proof grade Exd[ib]IIBT6, and optional intrinsically safe remote control, explosion-proof grade ExibIIBT6, measurable medium: drinking water, river water, sea water, ground water cooling water, high temperature water, sewage, lubricating oil, diesel, fuel chemical liquid, other homogeneous fluid.
External clip sensor parameters:
The external clip type sensor is an installation method in which the sensor is directly bundled on the outer surface of the pipe to be measured to realize flow measurement, and has a diameter independent of the pipe diameter.
Simple installation, no need to stop production, no pressure loss and so on.
According to different output signals, these products can be divided into LWGY-□N type and LWGY-□A type.
LWGY-□N type sensor: 12～24VDC power supply, three-wire pulse output, high level ≥8V, low level ≤0.8V; signal transmission distance ≤1000m;
LWGY-□A type transmitter: 24VDC power supply, 2-wire 4-20mA output, signal transmission distance ≤1000.
This type of turbine flow products are divided into basic type and explosion-proof type (ExdIIBT6).
2, intelligent integrated turbine flowmeter
Intelligent integrated turbine flowmeter adopts advanced ultra-low-power single-chip microcomputer technology to develop a new intelligent instrument integrating turbine flow sensor and display integration. It adopts double-row liquid crystal field display, with compact structure, intuitive reading and reliability. High, free from external power interference, lightning strike, low cost and other obvious advantages. The instrument has three-point correction of the meter coefficient, the intelligent compensation meter coefficient is nonlinear, and field correction can be performed. The high-definition LCD displays both instantaneous flow (4 significant digits) and cumulative flow (8 significant digits with clear function). All valid data is not lost after 10 years of power failure. These turbine flowmeters are explosion-proof products with an explosion-proof rating of ExdIIBT6.