Intelligent capacitance level meter

Productoverview:

ZW-LTS700 series Is the use of radio frequency capacitance detection technology, combined with industrial grade range measuring system of temperature drift compensation technology produced. In addition to its traditional capacitance (liquid) has the advantages of position detection technology, but also to solve the traditional capacitive (liquid) measurement system of temperature drift meter to overcome the large, poor resolution, detection of linear defects and poor. Can be applied to various industrial environments of measured medium components relatively stable soluble medium liquid level measurement and dry powder and granule material level measurement.

Two, work principle:

ZW-LTS700 series intelligent capacitance meter based on capacitive sensor, when the liquid level transmitter into the measured liquid in a certain depth, the pressure sensor at level formula: P = P.G.H + Po

Type:

P: welcome to the pressure liquid level transmitter

P: the measured liquid density

G: the local acceleration of gravity

Po: the surface atmospheric pressure

H: transmitter input liquid depth

At the same time, the pressure of the liquid into the positive pressure chamber through the gas sensor of stainless steel, then vacuum cavity pressure sensor and Po on the surface of the sensor is connected to offset on the back of the Po, the sensors for pressure: P.G.H, obviously, by measuring the pressure of P, can get the level of depth.

Three, application:

ZW-LTS700 series intelligent capacitive level meter can be of various liquid parameters is converted to a standard current signal and sent to the control room, for two meter or computer system of display, alarm or automatic control. The good structure and installation, suitable for continuous detection in high pressure, strong corrosion, easy to crystallize, easy to plug, anti cold junction under special conditions of liquid level, liquid level measurement can be widely used in electric power, metallurgy, chemical, food, pharmaceutical and other industries and sewage treatment, boiler, coal and other places.

Four, main features:

1, high performance capacitor materials: transmitter physical chemistry performance is extremely stable, so that products with high performance. The sensor precision up to + 0.02%FS, the stability is better than 0.05%FS, such high performance is the use of other products to achieve sensitive principle.

2, mechanical deformation: the sensitive capacitance die plate spacing tiny changes, can change the voltage signal can be measured, small mechanical deformation of the sensor hysteresis and repeatability error is greatly reduced, and the speed sensor is also improved.

3, wide measuring range, the pressure transmitter has a wide measurement range, it can be measured on 25Pa ~ 70MPa pressure accurately, and has high stability.

4, good long-term stability, pressure transmitter and other similar products, compared with higher stability, and other sensors such as metal strain sensor, creep capacitive pressure transmitter, temperature and aging effects are very small.The sensor affects almost all adverse factors on the output stability of capacitive sensor are less than other forms of.Pressure transmitter zero stability up to 0.05%FS/ years.

5, high pressure transmitter circuit output signal: the tiny change of capacitance is directly converted into high output signal without signal amplification, piezoresistive sensor (thin mode C) output signal is low, vulnerable to outside interference and other shortcomings, which is usually affected by temperature sensor stability is poor. The main reason, vulnerable to electromagnetic interference.

6, good corrosion resistance, pressure transmitter is in contact with the media, the material is made of stainless steel material, and thus many acid-base solution, corrosive gas or liquid good compatibility.

7, anti electromagnetic interference, high output signal, anti-interference design and use of metal and external electromagnetic field, pressure transmitter has a high rejection ability, and it has programmable control anti-interference ability is.

8, in the harsh environment: the pressure transmitter is very durable, its industrial products can withstａnd Zui 107 tested full-scale pressure cycle, if the working pressure is not, the cycle life of sensor is almost infinite, and the vibration of industrial products can withstａnd the impact of 100 ~ 200kg and Zui small 10~20.

Five, technical parameters:

Measuring range: 0.2-20 meters;

Accuracy: + 0.5% + 1%;

Probe temperature: -40~+250 degrees;

The transmitter to adapt to the environment temperature: -40~+60 degrees;

Allow the pressure: -0.1MPa~2.5MPa;

Medium: conductivity is not the end of the 10-3S/m of acid and alkali, water and other non conducting liquid crystal;

Power supply voltage: DC12-35V (isolated DC21-27V);

The non isolated line, three line: 20mA;

Three wire ends of isolation: <32mA;

Three terminal four line: <35mA;

Output signal: 4-20mA (0-10mA, 0-20mA);

Output protection: 27mA;

Voltage isolation between the measurement and the output power: 1000V;

Range adjustment range and zero migration: = + 30%FS;

The transmitter body size: 76 in diameter 85.

Six, installation and debugging:

1, liquid level transmitter with a plurality of installation, in order to adapt to different site conditions. When the site does not provide M20 * 1.5 internal thread or flange processing facilities, can choose the wall mounted, horizontal tube type and vertical tube type three installation options, make your handy in the on-site installation.

In 2, medium measuring greater liquidity, in order to prevent the sensor sharp swings the user can choose to play a stable weight attachment, the role of the sensor with weight must be to the weight of objects into the bottom of the container, so as not to pull the bad conductor.

3, in the field of environment is bad, the user should choose the sensor protection cover to protect the sensor, the measurement accuracy of the foreign body to avoid being damaged or infected.

4, the use of bar type liquid level transmitter, if not the metal containers, you need to put a wire connecting the bottom of the container with the transducer shell, otherwise the measurement is not accurate.

This product has been calibrated at the factory, if you need to adjust the site can take the following methods:

1, the debugging method of intelligent circuit:

The zero, when the liquid level in a Zui low, while holding down the "Z" button and the "S" button for 8 seconds and then release the "Z" button, the output current is automatically adjusted to 4mA.

Full - field adjusting when the liquid level is at Zui high, and press "Z" button and the "S" button for 8 seconds and then release the "S" button, the output current is automatically adjusted to 20mA.

2, the debugging method of analog circuit:

When the liquid level in the lower limit, the screwdriver is rotated slowly "Z" potentiometer, observe the meter readings close to 4mA.

When the liquid level in the cap with a screwdriver, slowly rotating "S" potentiometer, observe the meter readings close to 20mA.

So repeated 2-3 times or more, until the zero and span are respectively 4mA and 20mA accurately.

After adjustment, we should tighten the lid.

Seven, matters needing attention:

1, all products are supplied with product certificate and instructions including product number, technical parameters, wiring diagrams, etc. Please carefully check the date so wrong.

2, the installation should be according to the product connection and thread type, check whether the scene interface and product interface. If the thread interface should slow attention not to tighten, seal, torque is applied directly to the transmitter housing, only in the hexagonal transmitter interface.

3, the wiring should be in strict accordance with the requirements that the company use wiring.

4, this product can change the instrument precision, prohibit disassemble, collision and drop, forced to fight rejection.

5, the transmitter power can work, but 30 minutes warm-up stable output.

6, if abnormal, should turn off the power, stop using, check, or directly to the technical department of our company.

7, transportation and storage should restore the original packaging and store in a cool, dry and ventilated warehouse.

8, installation and use should pay attention not to induced wire break.

9, when installing the induction wire to the pool wall at least distance of more than 10CM, otherwise the measurement is not accurate.

The grounding wire 10, PTFE rod structure and the liquid level and the measured medium must be conducted, otherwise the measurement is not accurate.

11, the installation site should adopt effective lightning protection measures.

12, this series of any liquid level transmitter shell must be reliable grounding, grounding resistance should be less than 4.

13, safety gate should be made explosion-proof certification, the installation should be carried out according to the requirements of the specification.

14, when the transmitter for "0" when the security gate to the power transformer shall meet the requirements of Article 8.1 of the GB3836.4-2000.

Eight, the selection of encoding:

The selection of encoding: