The BT311 input type liquid level transmitter (also known as static pressure liquid level transmitter) uses imported corrosion-resistant diaphragm sensitive components, and the chip is installed in a stainless steel (or polytetrafluoroethylene) shell. The top steel cap serves to protect the sensor and also allows the measured liquid to smoothly come into contact with the diaphragm. This product uses a specially designed ventilation cable to ensure good communication between the back pressure chamber of the pressure sensing film and the atmosphere. The measured liquid level is not affected by changes in external atmospheric pressure, and the measurement is accurate, with good long-term stability and excellent sealing and anti-corrosion performance. It meets marine standards and can be directly put into water, oil and other liquids for long-term use. The PTFE material shell and cable can measure various highly corrosive liquids.

The unique internal structure technology completely solves the problem of condensation and dew.
Using specially designed electronic design technology to completely solve the problem of lightning strikes.

Technical parameters and structural dimensions of BT311 input type liquid level transmitter

Structural size Class A cable type integrated

Stainless steel (1Cr18Ni9Ti) shell, polytetrafluoroethylene shell with junction box, split type liquid level transmitter

The transmitter only has a pressure probe inserted into the liquid, and the circuit part is located in the junction box at the other end, which can be easily adjusted by the user. Installation method: Class B junction boxes can be installed in two forms: M42 × 1.5 threaded installation or DN50 PN0.6 (GB9119-88) standard flange installation; The C-type junction box has installation holes ranging from 3 to 8 (evenly distributed on a circle of 134). The pressure probe of the split type liquid level transmitter is made of stainless steel (1Cr18Ni9Ti) material, and the cable sheath is made of rubber. For special requirements, PTFE probes, stainless steel, or PTFE cable sheath materials can be selected.

The pressure probe and cable sheath of the pole type armored liquid level transmitter are made of all stainless steel (1Cr18Ni9Ti) material, and the insertion depth of the transmitter can be freely adjusted within ± 20cm.
B-class junction box (plan view)

C-type junction box (top view)

User provided flange (DN50 PN0.6 standard flange)

B-type junction box flange and thread installation structure diagram
1) Cable flange installation 2) Cable thread installation 3) Rod flange installation 4) Rod thread installation

Installation Diagram

Install in container

Selection Table


Electrical schematic diagramNote: Due to improvements, this schematic diagram may be modified without prior notice. We apologize for any inconvenience caused!

Installation requirements and precautions
Before installation, please check whether the model, range, and working power supply indicated on the label are consistent with the usage site.
2. This product can be directly put into the liquid to be tested, or it can be installed on the pipeline (or container wall) using the M20 × 1.5 (or M27 × 2) interface without the need for a bracket. Different installation positions may result in zero point errors, but they can be corrected and have no impact on the measurement range. To avoid the accumulation of solid sediment or other viscous substances in the measuring medium, which may affect the measurement accuracy, it is recommended to install the product with the inlet hole vertically downward (or tilted downward at a certain angle).
When measuring high-temperature media, please use a pressure tube or other cooling device to lower the temperature to the allowable temperature range of the transmitter.
When installing outdoors, try to place the transmitter junction box (or lead out) in a dry place as much as possible, avoiding direct sunlight and fish rain, otherwise it may cause the transmitter performance to deteriorate or malfunction.
5. The transmitter should be installed in areas with small temperature gradients and fluctuations, while avoiding strong vibrations and impacts.
6. If the medium to be tested is viscous or has sediment, please choose a non cavity, membrane exposed structure, and clean it regularly to avoid errors. For other special applications, please specify the requirements when ordering, and we can make specialized products.
7. The performance of the transmitter has decreased beyond the compensation temperature range.
When the ambient temperature and the temperature of the measuring medium suddenly change, the transmitter signal will jump, which is a normal phenomenon. After the ambient temperature and medium temperature stabilize, the transmitter output signal will also stabilize.
9. Non trained personnel are not allowed to disassemble the transmitter at will to avoid damage. If the transmitter malfunctions, please return to the company or have it repaired under the guidance of professional technicians.
10. Liquid level transmitters are precision measuring instruments and should be calibrated regularly by relevant metrology departments.
Before using the product, please read the accompanying "Operation Manual" carefully.

Warning! Any of the following situations may result in irreparable damage to the product.
1. The measured pressure value exceeds the "overload capacity" of the product (see the product's factory inspection certificate).
2. Power supply>45VDC or AC power supply.
3. Insert a hard object into the pressure hole.
4. Measurement of corrosive or beer, hydrogen and other media, but not specified when ordering.

electrical connection

Attention: Do not adjust the range (S) potentiometer without measuring equipment.

On site wiring diagram: Z - Zero adjustment potentiometer S - Full adjustment potentiometer

verify
1. The transmitter has been adjusted to the optimal range and accuracy according to user needs before leaving the factory, and generally does not require calibration.
2. The following situations need to be rechecked: A) Falling, strong vibration, and collision during transportation; B) Placed for more than six months; C) After long-term operation, there may be errors greater than the accuracy range; D) Routine inspection by the using unit.

3. Calibration instruments

4. Verification step A) Connect the testing equipment and the tested transmitter as shown in the following figure.

B) Apply rated pressure to the transmitter three times and maintain it at rated pressure for 10 seconds. After each load, return to the zero pressure point.
C) Close 2 and open 3, so that the transmitter is well connected with the atmosphere. After stabilizing, adjust the "Z" potentiometer, and use the multimeter to read "4.00mA".
D) Close 3, open 2, and use the pressure signal generator to fill the range pressure signal of the transmitter. （6mH2O）， After the pressure is stable, adjust the "S" potentiometer so that the multimeter reading is "20.00mA". (Note: The adjustment of transmitter zero and sensitivity needs to be repeated several times until it meets the requirements. No further adjustments are allowed during the entire static calibration process thereafter.)
E) The number of calibration points shall not be less than 6 (including zero and full range). It is best to select uniformly according to the measurement range. After stabilizing for 20 seconds at each calibration point, read the output value.
F) Gradually increase the pressure according to the selected calibration point for testing. After reaching the upper limit pressure of the rated range, increase the pressure to 110% of the rated range and hold for 1 minute. Then reduce the pressure to the rated range. After stabilizing for 20 seconds, read the output value as the full-scale output value of the return stroke. Gradually reduce the pressure to the lower limit of the rated range, with the forward and reverse strokes as one cycle. Repeat three cycles for each transmitter.
G) After verification, equip all accessories in order, tighten all parts, and ensure sealing performance.