product overview

3351LT flange type liquid level transmitterThe two pressures of the measured medium are introduced into the high and low pressure chambers, acting on the isolation diaphragms on both sides of the δ element (i.e. sensitive element), and transmitted to both sides of the measuring diaphragm through the isolation diaphragms and the filling liquid inside the element. The DC-3851/1851LT series flange type liquid level transmitter consists of a measuring diaphragm and electrodes on both sides of the insulating film, each forming a capacitor. When the pressure on both sides is not consistent, it causes displacement of the measuring diaphragm, which is proportional to the pressure difference. Therefore, the capacitance on both sides is unequal. Through oscillation and demodulation, it is converted into a signal proportional to the pressure.

The working principle of pressure transmitters and absolute pressure transmitters is the same as that of differential pressure transmitters, except that the pressure in the low-pressure chamber is atmospheric pressure or vacuum. The A/D converter converts the current of the demodulator into a digital signal, which is used by the microprocessor to determine the input pressure value. The microprocessor controls the operation of the transmitter. In addition, it performs sensor linearization, resets measurement range, engineering unit conversion, damping, square root, sensor fine-tuning and other operations, as well as diagnosis and digital communication. The D/A converter fine tunes the digital signal from the microprocessor, which has been calibrated. This data can be modified using transmitter software and stored in EEPROM, ensuring complete preservation even in the event of a power outage. The digital communication line provides a connection interface for the transmitter to external devices (such as the 205 smart communicator or control system using HART protocol). This line detects the digital signal superimposed on the 4-20mA signal and transmits the required information through the loop.

Product Features

• Super measurement performance, used for pressure, differential pressure, liquid level, and flow measurement;
• Digital accuracy: ± 0.05%;
• Simulation accuracy: ± 0.75%, ± 0.1% F.S;
• Full performance: ± 0.25F S；
• Stability: 0.25% for 60 months;
• Range ratio: 100:1;
• Measurement rate: 0.2S;
• Compact (2.4kg) all stainless steel flange, easy to install;
• Process connectivity is compatible with other products to achieve optimal measurement;
• The sensor with alloy sheath achieves excellent cold and hot stability;
• Intelligent transmitter using 16 bit computer;
• Standard 4-20mA, with digital signal based on HART protocol, remote control;
• Support the upgrade to fieldbus and field control based technologies.

Selection instructions

The DC-3851/1851LT flange type liquid level transmitter can accurately measure the liquid level and density of various containers. There are flat flanges and plug-in flanges to choose from, with flanges of 3 inches or 4 inches and specifications of 1501b and 3001b. The flange can also be customized according to the user, and the flange membrane sheet material is optional.

Ordering Instructions

1. The transmitter model can be determined according to the selection specification table as needed.
2. The numbers and symbols in the selection specification table must be filled in clearly and accurately.
3. If there is positive or negative migration, the migration amount value must be indicated.
4. If a differential pressure transmitter needs to be equipped with a three valve group, it needs to be specified separately.
5. When selecting a remote transmitter, it should also be determined according to different remote flange selection tables as needed.
6. If the remote transmitter is to be used in vacuum and high temperature environments, it should be specially marked when ordering.
7. The materials for the contact medium O-ring include nitrile rubber and fluororubber.
8. Unless otherwise specified, the filling fluid at the factory is silicone oil.