The choice of electromagnetic flowmeter is mainly the correct choice of the transmitter, and the converter only needs to be matched with it.
Choice of caliber and range
The diameter of the transmitter is usually the same as that of the piping system. If the piping system is to be designed, the diameter can be selected according to the flow range and flow rate. For electromagnetic flowmeters, the flow rate is suitable for 2 - 4m / s. In special cases, such as solid particles in the liquid, in consideration of wear, the optional flow rate is ≤ 3m / s, for easy to manage the fluid. Available flow rate ≥ 2m / s. After the flow rate is determined, the transmitter diameter can be determined according to qv= D2.
The range of the transmitter can be selected according to two principles: one is that the full scale of the meter is greater than the expected maximum flow value; the other is that the normal flow is greater than 50% of the full scale of the meter to ensure a certain measurement accuracy.
Temperature and pressure selection
There are certain restrictions on the fluid pressure and temperature that the electromagnetic flowmeter can measure. When used, the pressure used must be lower than the working pressure specified by the flowmeter. At present, the working pressure specifications of domestically produced electromagnetic flowmeters are:
Less than 50mm caliber, working pressure is 1.6MPa; 900 mm caliber, working pressure is 1 MPa;More than 1000mm caliber, working pressure is 0.6MPa.
If there are special requirements on the pressure resistance of the transmitter, you can negotiate with the manufacturer.
The operating temperature of the electromagnetic flowmeter depends on the lining material used, which is generally 5 - 70 ° C. Such as special treatment, can exceed the above range, such as the wear-resistant corrosion-resistant electromagnetic flowmeter produced by Tianjin Automation Instrument No.3. The transmitter allows the measured medium temperature to be -40 to 130 °C.
Selection of lining material and electrode tree material
The lining material and electrode material of the transmitter must be correctly selected according to the physical and chemical properties of the medium. Otherwise, the instrument will be damaged quickly due to the corrosion of the lining and the electrode, and the corrosive medium will easily cause an accident if it leaks. Therefore, the electrode and the lining material must be carefully selected according to the specific measurement medium in the production process.
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.
Liquid turbine flow meter classification and function description
Keywords: liquid turbine flowmeter, diesel liquid turbine flowmeter, pure water liquid turbine flowmeter
First, the liquid turbine flowmeter overview
The liquid turbine flowmeter is the main type of impeller flow (flow rate) meter, and the impeller type flowmeter also has an anemometer and a water meter. The TUF consists of a sensor and a conversion display. The sensor uses a multi-blade rotor to sense the average flow rate of the fluid, thereby deriving the flow or total amount. The rotational speed (or number of revolutions) of the rotor can be detected mechanically, magnetically, and photoelectrically and displayed and transmitted by the reading device.
Second, liquid turbine flowmeter classification
According to the classification of instrument functions, SDLWGY series turbine flowmeters can be divided into 2 categories.
1, turbine flow sensor / transmitter
2, intelligent integrated turbine flowmeter
Third, the liquid turbine flowmeter function description
1, turbine flow sensor / transmitter
This type of turbine flow product itself does not have a live display function, only the flow signal is transmitted far. The flow signal can be divided into pulse signal or current signal (4-20mA); the instrument is low in price, high in integration and small in size, and is especially suitable for use with computer control systems such as secondary display, PLC, DCS.