Description:
Productoverview:
ZW-LT703 series RF induction type liquid level meter the introduction of similar foreign products, technology and the. It has the advantages of compact structure, small volume, simple installation and maintenance, uniform size. Multiple signal output form, convenient for different system configuration. Teflon probe, acid, alkali and other strong corrosive liquids and high temperature. Measuring part in liquid, only a PTFE or PTFE wire rod as the sensing probe, high reliability. Full sealed Aluminum Alloy shell and stainless steel fasteners. The output ends of measurement, and measurement, power output, three terminal circuit structure with multiple isolator, isolator, adapt to different signal grounding
Two, work principle:
ZW-LT703 series anticorrosion capacitive levelmeter electric induction principle, the measured medium immersion probe height changes, reflecting the induction frequency changes, the circuit and the corresponding 4~20mA current signal output. That is generated by the CPC calibration signal and the measured signal value from the medium value and the difference operation is converted to the actual level. When the transmitter is put into a position in the liquid, the pressure sensors: P = 9.80665, P H
The P effect of the liquid pressure on the sensor unit, kPa
P a liquid density, g / cm3
H to measure the height of liquid level, M
So H = 0.10197P / P
To feel the pressure transmitter signal is converted into an electrical signal, and the signal is proportional to the height of liquid.
Third, application:
ZW-LT703 series anticorrosion capacitive level meter can be applied to high pressure, high temperature, strong corrosion, easy crystallization, anti blocking, anti freeze and solid powdery and granular materials under the special circumstances of the liquid level or level of continuous detection, used in various industrial process detection and control.
Four, main features:
1, simple structure, without any movable or elastic element, so stay on very little maintenance.
2, convenient installation: the built-in structure especially show this characteristic, without any special tools.
3, easy to adjust the zero range, two potentiometers can be arbitrary zero migration or range in level detection range change, two adjustments do not affect each other.
4, a wide range of uses: liquid level measurement is suitable for high temperature and high pressure and corrosive medium.
Five, technical parameters:
1, the effective detection range: 0-0.2-20m;
2, accuracy: 0.5 grade and 1 grade, 1.5 grade;
3, pressure range: negative pressure and high pressure below 32MPa;
4, working temperature: -50 to 240 DEG c;
5, the ambient temperature to 75 DEG C: -20;
6, suitable medium: any medium of acid and alkali, salt or no corrosion of ptfe;
7, the output signal 4-20mA, two-wire system;
8, the power supply load resistance of 0-750 ohm DC24V;
9, fixed mode: screw mounted M20 * 1.5 and M27 * 2 DN15, DN25, DN50 flange, DN80;
10, the scene display: analog display 0-99%, digital display, depth of field.
Six, measurement system:
The measurement system is intrinsically safe.
This type of pressure, differential pressure transmitter with intrinsically safe circuit, suitable for explosive hazardous area explosion-proof grade ExiallCT4-CT6.
In system loop shielded signal cable must be used, and reliable grounding. The measurement system wiring diagram only to the output signal of 4-20mA and 0-10mA as an example,
The liquid level transmitter has the advantages of reliable operation, stable performance, small size, light weight, low cost, design a variety of forms, convenient installation, no need to support. Electronic circuit board with microprocessor based, can automatically eliminate the influence of temperature change on the sensor accuracy.
This series of products can be equipped with liquid crystal display LCD for local operation.
Intelligent output at the same time with HART communication function.
Seven, installation and debugging:
Cable type and lever type 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 3 installation options, make your handy in the on-site installation.
In the measurement of dielectric greater mobility, 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.
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.
The use of ZW602 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:
A: the debugging method of intelligent circuit:
The zero - position when the liquid level is low, and press the key of "Z" and "S" button for 8 seconds at the same time. Then, click "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 at the same time. Then, click "S" button, the output current is automatically adjusted to 20mA.
B: 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.
Eight, installation and notice:
Appearance and installation:
The liquid level transmitter is composed of a casing, an amplifier, terminals, protective cap, hollow wire etc., according to the needs of the user can use the pointer table, liquid crystal display meter.
Installation method:
The choice of local easy operation and maintenance for installation;
It should be kept away from the vibration source installation;
It should be kept away from heat sources;
The input mounted liquid level transmitter, the metal probe to sink into the bottom of the container.
Nine, 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 six party interface on the transmitter.
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 the preheating 30 minutes output stability.
6, if abnormal, should turn off the power, stop using, check, or directly to the technical department of our company.
7, transport 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.
10, encoding selection:
Type spectrum | Explain |
ZW-LT70 |
| Capacitance level meter (Zhongwei control) |
category | One |
| Cable type |
Two |
| Rod type (sensor is installed at the bottom, direct contact with liquid medium) |
Three |
| Antiseptic |
Four |
| The guide rod (pressure sensor mounted on the upper part, is not in direct contact with the media) |
Process connection form | T |
| Mounting bracket |
N |
| Flange mounting DN40 PN1.0 |
K |
| Tri-Clamp |
Y |
| Special agreement |
Connect the sensor material | One |
| Three hundred and four | Bar type |
Two |
| Three hundred and sixteen |
Three |
| 316L |
Four |
| Ding Qing rubber and PVC Composites | Cable type |
Five |
| PTFE (polypropylene flange) |
Proof way | O |
| No explosion |
E |
| Explosion-proof Exia II CT6 |
Display mode | O |
| Without on-site instructions |
Z |
| With current meter indication ( 0-99% Scale) |
X |
| With on-site display |
The weight of | O |
| Without counterweight |
W |
| Need to balance |
| -. |
| The installation height ( Mm ) |
| -. |
| Measurement of height ( Mm ) |
| -. | The measured medium density ( G/cm3 ) |
Eleven, 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 flange nominal diameter, DN20, DN25, DN50, DN80, DN100 etc.;