The two pressures of the flange level transmitter of the measured medium pass into the high and low pressure chambers acting on the isolation diaphragm of the element (i. e., the sensitive element) and transmitted to both sides of the measuring diaphragm through the isolation diaphragm and the filler fluid inside the element.The flange level transmitter is made of a measuring diaphragm with two insulating insulation

The electrodes each form a capacitor.When the pressure on both sides is inconsistent, the measurement diaphragm produces a displacement, its displacement amount is proportional to the pressure difference, so the electric capacities on both sides are different, through the oscillation and demodulation link, converted into a signal proportional to the pressure.                                   

Characteristics

 ● high accuracy and good stability.

● second-line working mode, 4~20mA or 0~10mA signal output.

● sensitive parts and circuit boards are fully solid and vibration resistant.

● has strong anti-interference ability and good temperature stability;

● explosion-proof shell structure, available all weather.

● has the best corrosion performance, ensure the best cost corrosion performance.

● structure is light, simple and reasonable, no support, no horizontal installation, can be installed directly at any position.

Working principle

Principle

During operation, the isolation diaphragm on the high and low pressure sides and the filling fluid will transfer the process pressure to the central filling fluid, and the central filling fluid will transfer the pressure to the sensing diaphragm at the center of the δ— chamber sensor.The sensing diaphragm is a tensional elastic element whose displacement varies with the differential pressure (for the GP surface pressure transmitter, the atmospheric pressure is as applied on the low pressure side of the sensing diaphragm).AP booster transmitter, the low pressure side always maintains a reference pressure.The maximum displacement of the sensing membrane is 0.004 inches (0.10 mm).The displacement amount is proportional to the pressure.The amplifier circuit of the two capacitance fixing plates of the measurement diaphragm is linearly converted into a second-line current, voltage, or digital HART(high-speed addressable remote transmitter data highway) output signal of 4~20mA DC

Main technical indicators

Technical indicators

Use the object liquid, gas, or steam

Range  pressure: 0~10Kpa ~7Mpa;

Negative pressure: -100KPa ~7MPa

Output 4~20mADC

Power supply is 12~45VDC

Load feature 4~20mADC second-line production load

R ≤ 50 (V13) (see Figure-2)

Temperature Range Environmental temperature: -40~+ 85℃;

Storage temperature: -40~+ 85℃

Standard medium temperature: -20~+ 104℃

The enclosure is better than IP65

Explosion-proof type type ia Ⅱ CT5 shall be equipped with external safety grille

Performance indicators

Comprehensive precision: The standard provides 0.25%, the maximum accuracy of ± 0.1%BFSL stability is better than ± 0.1%BFSL/ years

Temperature effect: in the range of-20~+ 70℃, the change amount is less than ± 0.18% / 10℃

Vibration effect: if the vibration frequency of 20.00% Hz in any direction is less than 20-200% BFSL

Impact : After 11 ms of 100G in any direction, the change is less than ± 0.02% BFSL

Load impact: No load effect as long as the terminal voltage of the input transmitter exceeds 12V,There was no position effect

Structural indicators

Structural materials

Membrane sheet: silicon

Case: low copper cast aluminum

Contact medium material: SUS304

"Type O" ring sealing structure: nitrile rubber, polytetrafluoroethylene, or fluorine rubber

Process Connection: Flange connection to the Flanged connection

Electrical connection: It can be drawn from either outlet as required and it is recommended to use φ 10 industrial cable as the lead for sealing.

General cable connector may be selected: PG16 or M20 × 1.5 without lead end sealed with end cover.

Structure and installation method

Figure-4 is the flange structural schematic and dimension table unit (mm)

1. It is installed directly on the measurement point (at any angle).

2. tries to install on pressure measurement with small temperature gradient and temperature fluctuations, while avoiding strong vibration and shock.

3. outdoor installation, place in the protective box as much as possible from direct sunlight and rain to maintain transmitter performance stability and extended service life.

4. When measuring steam or other high temperature medium, be careful not to overlimit the operating temperature of the transmitter.Install the radiator or other cooling device connection when necessary.

5. installation, the pressure stop valve shall be installed between the transmitter and the medium to repair and prevent the blocked pressure outlet and affect the measurement accuracy.In the pressure fluctuation paradigm Damper or pressure buffer shall also be added for the enclosure.

Note: The components or structures that may affect the explosion-proof performance shall not be replaced or changed at will.

System connection and commissioning

The transmitter is recommended to choose the power supply voltage Us of 24V. in the systemDC .

The resistance value of the sampling resistance (load resistance) RL in the secondary instrument is 250 Ω.If Us and RL choose other values, then the RL value cannot exceed the value calculated by the formula.

The power supply is connected to the transmitter through the signal cable. The connection holes on the top sides of the transmitter are sealed by cable or signal cable. The signal cable is locked by the fastening nut, and the unused connection port must be sealed.

Wiring diagram of the A: measuring system

The shielding signal cable must be used in the system circuit and reliably grounded.

The transmitter has been factory according to the user needs, the range, accuracy have been adjusted to the best condition, generally need not check.However, the following conditions shall be rechecked:

A.Drop, strong shock and collisions in transport;

B.Storage period is more than one year;

C.After long operation, an error greater than the range of accuracy;

D.Routine inspection of the use unit.