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Instrument knowledge | double flange differential pressure transmitter

Dec 06, 2018

Instrument knowledge | double flange differential pressure transmitter


Differential pressure transmitter is a transmitter that measures the pressure difference between the two ends of the transmitter and outputs standard signals (such as 4~20mA, 0~5V).Differential pressure transmitter and general pressure transmitter different is that they have 2 pressure interface, differential pressure transmitter is generally divided into positive pressure end and negative pressure end, in general, differential pressure transmitter positive pressure end pressure should be greater than the negative pressure section pressure can be measured.

Instrument knowledge | double flange differential pressure transmitter

Analog characteristic

●High precision

●The range, zero external continuous adjustable

●Good stability

●The positive migration up to 500%, negative migration up to 600%

●When two wire

●Adjustable damping, resistance to overpressure

●Solid sensor design

●No mechanical moving parts, less maintenance

●Light weight (2.4kg)

●The whole series of unified structure, strong interchangeability

●Miniaturization (total height 166mm)

●Diaphragm material for contact media is optional

●Unilateral resistance to pressure

●Low pressure cast aluminum alloy shell

Intelligent features

●Super measurement performance for pressure, differential pressure, liquid level, flow measurement

●Digital accuracy: plus or minus 0.25%

●Simulation accuracy: + + 0.5% + 0.1%F.S

●Total energy: + / - 0.25F.S

●Stability: 0.25% for 60 months

●The range ratio: 100:1

●Measurement rate: 0.2s

●Miniature (2.4kg) stainless steel flange, easy to install

●The process connection is compatible with other products to achieve the best measurement

●The world's only H alloy sheath sensor (patented technology), to achieve excellent cold, thermal stability

●The use of 16 - bit computer intelligent transmitter

●Standard 4-20ma, with HART protocol based digital signal, remote control

●To support the upgrading of fieldbus and field-control-based technology.

Differential pressure/pressure transmitter with remote transmission device provides a reliable measurement method to avoid direct contact between the measured medium and the isolation diaphragm of the transmitter.

Instrument knowledge | double flange differential pressure transmitter

Transmitter with remote transmission device is suitable for the following working conditions:

1. High temperature media shall be isolated from the transmitter.

2. The measuring medium has corrosion effect on transmitter sensitive elements. 

3. The medium under test solidifies or crystallizes due to changes in environment or temperature.

4. The measuring head shall be strictly purified to replace the medium under test

5. Suspension liquid or medium with high viscosity

6. The measuring head must be kept clean and hygienic.

7. Measurement of sealed pressure vessel.

Installation instructions

In fact, you may notice that the 4-20ma current itself can power the transmitter, as shown in figure 1.The transmitter is equivalent to a special load in the circuit. What is special is that the current consumption of the transmitter varies from 4 ma to 20mA according to the output of the sensor.The display instrument only needs to be serialized in the circuit.This transmitter only needs to connect 2 wires externally, so it is called two-wire transmitter.The standard lower limit of industrial current loop is 4mA, so as long as it is within the range, the transmitter has at least 4mA power supply.This makes the design of two - wire sensor possible.

In industrial applications, measurement points are usually on site, while display or control equipment is usually in the control room or control cabinet.The distance between the two can be tens to hundreds of meters.According to the calculation of distance of 100 meters, saving 2 signal transmission wires means reducing the cost by nearly 100 yuan!In addition, the four-wire system transmitter and the three-wire system transmitter must use the expensive shielded wire because of the current asymmetry in the wire, and the two-wire system transmitter can use the very cheap twisted-pair wire wire, so the two-wire system transmitter must be the first choice in the application.

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