Explosion-proof positive and negative pressure transmitter

I. Product Overview:

The application of digital technology in ZW3351SP series explosion-proof positive and negative pressure transmitter not only ensures the high reliability and other superior performance of the instrument, but also realizes the real-time self-checking configuration operation of the intelligent instrument and the remote digital connection between the control room and the control room, and realizes the remote inquiry or real-time configuration of the unit instrument in the control room. High accuracy and good stability. Range, zero external adjustable. Miniaturization, light weight, strong vibration resistance. No mechanical moving parts, reliable operation, easy maintenance. Solid element, plug-in printed circuit board. Explosion-proof structure, can be used all day.

II. Working Principle:

ZW3351SP series explosion-proof positive and negative pressure transmitters measure two kinds of pressure into high and low pressure chambers, which act on the two sides of the isolation diaphragm of the delta element (i.e. the sensitive element), and transmit to the two sides of the measurement diaphragm through the isolator and the filling liquid in the element. A capacitor is formed by measuring the diaphragm and the electrodes on both sides of the insulating sheet. When the pressure on both sides is inconsistent, the displacement of the diaphragm is proportional to the pressure difference, so the capacitance on both sides is different, and the signal is converted into a signal proportional to the pressure through oscillation and demodulation.

3. Application occasions:

ZW3351SP series explosion-proof positive and negative pressure transmitters are mainly used to measure the pressure, negative pressure and adiabatic pressure of gas, liquid and steam, and then convert them into 4-20mA.DC signal output. High-precision pressure transmitter can communicate with each other through HART protocol-compliant hand-operated devices. It can measure the pressure of exhaust system, distillation tower, evaporator and crystallizer.

Fourth, main characteristics:

1. Super measurement performance for pressure, differential pressure, liquid level and flow measurement;

2. Digital accuracy: +(-) 0.05%;

3. Stability: 0.25% for 60 months;

4. Range ratio: 100:1;

5. Measurement rate: 0.2S;

6. Miniaturized (2.4kg) stainless steel flange, easy to install;

7. Process connection is compatible with other products to achieve ideal measurement.

8. The sensor (technology) with H-alloy sheath has achieved excellent cold and thermal stability.

9. Using 16-bit computer;

10. Standard 4-20mA, with HART-based digital signal, remote control supports upgrading to fieldbus and field control technology.

Technical parameters:

1. Targets: liquids, gases and vapors;

2. Measurement range: 0-40 Mpa;

3. Output signal: 4-20mA DC (special for four-wire system); 220V AC power supply, 0-10mA DC output;

4. Power supply: 12-45V DC, generally 24V DC;

5. Load characteristics: related to power supply, with load capacity at a certain power supply voltage; the relationship between load impedance RL and power supply voltage Vs is: RL < 50 (Vs-12);

6. Indicator table: pointer linear indicator 0-99% calibration and LCD liquid crystal display;

7. Explosion-proof grade: a: Exd II BT5 or Exd II CT6; b: intrinsically safe type (Exia II CT6 or Ex IB II CT6).

6. Installation requirements and precautions:

1. Before installation, please read the product instructions carefully and check the relevant information of the product.

2. Transmitters should be installed in ventilated, dry, non-corrosive and shady places. If installed in the open air, protective shields should be added to avoid sunshine and rain, and to avoid performance degradation or failure of transducers.

3. Transmitter is a precise instrument. When installed, avoid strong impact and smash.

4. Connect correctly according to wiring diagram.

5. Attention should be paid to protecting the lead-out cable of the transmitter. It is suggested to use metal pipe to protect or overhead when using in industrial field. Do not loosen the sealing nut of the cable lead-out end to avoid moisture entering.