Capacitance materiallevel meter

Productoverview:

ZW-LT700 series The variable capacitor form has the advantages of simple structure, durable and very stable, variable capacitor is composed of diaphragm pressure cavity and fixed on the insulated electrode, when feeling the pressure changes, the diaphragm to deform slightly, thus changing the pole spacing, by small changes in measuring capacitance by unique detection circuit the linear processing and temperature compensation and. DC voltage or current sensor output signal and the measured pressure is proportional to the.

Two, work principle:

ZW-LT700 series capacitance materiallevel meter is due to the change of liquid level of liquid, surrounded by the probe line area change, lead to changes in capacitance, capacitance signal processing and microprocessor acquisition, display and output. The principle of capacitance method for liquid level measuring probe line and the conductive liquid constitute a capacitor, wherein the probe wire core for capacitor pole, the conductive liquid for another pole of the capacitor, the middle high stability of ptfe. With the change of liquid level of liquid, surrounded by the probe line area change, cause the capacitance changes according to the concentric cylindrical capacitance formula can be written and is the relationship between the height of liquid:

C=Co 2 pi epsilon /LogD/d*h type:

Co: distributed capacitance

E: PTFE dielectric constant

D: probe diameter

D: probe diameter

H: a liquid immersion probe for height, Co, e, D/d as a constant, so that the electric capacity of C=kh, only with a liquid immersion probe is proportional to the height of the pole.

Three, application:

ZW-LT700 series capacitance materiallevel meter can be of various liquid parameters is converted to a standard current signal and sent to the control room, for secondary instrument or computer system of display, alarm or automatic control. The good structure and installation, suitable for metallurgy, chemical industry, environmental protection, power, papermaking, printing and dyeing, pharmaceutical, food, municipal and other sectors of the liquid level, oil-water interface and foam interface of continuous monitoring. This is not suitable for viscous liquid level measuring instrument in medium viscosity is greater than 125mm2/s.

Four, main features:

1, a variety of signal output form, convenient for different system configuration;

2, PTFE probe, acid, alkali and other strong corrosive liquids (except sodium outside) and high temperature;

3, the measurement part, only a PTFE or PTFE cord rod probe as a sensor, high reliability;

4, can be used for high temperature and high pressure situations and the measured value is not affected by the temperature of the fluid to be measured, the proportion and the shape of the container, the influence of pressure;

5, two-wire LED scene display, without power, completely solve the LCD cannot be displayed in the dark environment problems;

6, perfect overcurrent and overvoltage protection and power supply polarity protection.

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: Phi 76 * 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 - position when the liquid level is low, at the same time, press 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 high, at the same time, press the "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.

Repeat 2-3 times, until the zero and span are respectively 4mA and 20mA accurately.

After adjustment, we should tighten the lid.

Seven, installation and use:

1, we must try to keep the poles and the tank wall (or auxiliary probe) parallel, especially flexible probe to tighten and fixing measures at the bottom of the tank.

Six angle bolts 2, installation wrench screwing process connection, do not use force on other parts.

3, probe properly near the tank wall is helpful to improve the measurement sensitivity.

4, above the container for feeding, the probe should be kept away from the inlet, and avoid the material directly to probe on the splash.

5, no auxiliary probe, should ensure that the instrument is connected with the container at good contact (contact resistance between the container and the instrument is less than 1 ohms).

6, after wiring, tighten the cable joint locking cap.

7, the medium temperature is higher than 100 DEG C, the sensor must custom heat dissipation structure.

Eight, the selection of encoding:

Nine, design selection and ordering information:

1, specifications: ZW-LT700 series capacitance level meter;

2, the measured medium Name: medium density;

3, measurement range: also known as nominal length;

4, working pressure: pressure;

5, working temperature: measure the temperature of the liquid;

6, material requirements: wetted materials;

7, supporting the supply of flanges, bolts and nuts, valve, sealing washers and other accessories;

8 standard: flange and flange nominal diameter, DN20, DN25, DN50, DN80, DN100 etc.;

Special requirements: 9, please indicate in detail before ordering.

9, customer service service commitment:

1, I sold by the company level transmitter series product quality problems within 12 months, responsible for free maintenance.

2, the warranty period if the products of our company have any quality problems, our company is responsible for free repair or replacement.

3, the warranty period if the user use undeserved, cause damage to the product, our company is responsible for the maintenance, collect the damaged parts cost.

4, after the warranty period of product quality problems, our company is responsible for the maintenance, collect the damaged parts cost.

5, if the user needs to our service, our company in the province of the user service personnel arrived at the scene within 12 hours, arrived at the scene 48 hours outside users.