Bar type guided wave radar level gauge

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Rod guided wave radar level gauge is main technical indicators meet or exceed similar products at ho…

Products overview:

ZWRD702 seriesBar type guided wave radar level gaugeMicrowave pulse along a rod or contain a rod of coaxial casing running, access to the measured medium, microwave pulse is reflected back, and receive electronic components, and calculated its running time.Microprocessor recognition level echo, after the analysis and calculation to convert it to a signal is given.Because of its simple measuring principle, can adjust without material, thereby saving a large amount of debugging.Measuring line or rods can be shortened, and make it more adaptable to the scene of the application.Is not sensitive to steam, even in the smoke, noise, steam under the condition of strong, measurement accuracy is not affected.Is not affected by changes in the dielectric properties, the dielectric constant of medium density changes or changes will not affect measurement accuracy.Adhesion: no problem, in the probe or container wall adhesion medium will not affect the measurement result.Container install content if coaxial bushing measuring completely unaffected by container of installation, no special debugging.

Second, the working principle:

ZWRD702 series lever type guided wave radar level meter is the measuring instrument based on the principle of time travel, very low energy is emitted by a very short microwave pulse by transmitting and receiving antenna system.Radar wave are running at the speed of light.Running time can be transformed into material level signal by electronic parts.Probe a high-frequency pulse and probe the conduction along the cable type or rod type, when the pulse in the material surface reflected by the receiver inside the instrument, and the distance signal is transformed into material level signal.A special type of time extension method can guarantee the stability of a very short period of time and accurate measurement.Even if the condition is relatively complex, false echo, with a new micro processing technology and debug software can accurately analyze the level of the echo.

1, the input:

Reflection of the pulse signal along the cable type or bar type probe to the instrument electronic circuit part, microprocessor to signal processing, identify the microwave pulse produced by the echo in the material surface.Correct echo signal recognition by intelligent software to complete, distance material on the surface of the distance D is proportional to the pulse of time travel T: D = C * T / 2 where C is the speed of light because of the distance of the empty cans E known, the level of L: L = E - D;

2, the output:

By entering empty cans height E (= zero), full tank height F (= full scale) and some applications to set parameters, application parameters will be automatically adapt instrument to measure the environment.Corresponding to the four...20 ma output;

3, measuring range:

F - measurement range;E - empty cans distance;B - the top blind area;H - probe zui small distance to the tank wall at the top of the blind area zui high material refers to material surface and measuring zui small distance between the reference point.At the bottom of the blind area is located near the bottom of the cable zui unable to accurately measure the distance.At the top of the blind area and at the bottom of the blind area is effective measuring distance between;

4, note: only the material between the top blind area and at the bottom of the blind area, to guarantee the reliable tank level measurement.

Applications:

ZWRD702 series double cable type guided wave radar level gauge is suitable for high temperature (350 ℃), high pressure, high vacuum, steam, dust and bad environment such as volatile gas.For continuous measurement of different materials.The instrument main technical indicators meet or exceed similar products at home and abroad, and convenient installation and debugging, can use a single, also can use network, can be widely used in metallurgy, building materials, energy, petrochemical, water conservancy, food and other industries.

Four, the data processing:

By entering a empty cans height (L = zero), full fill height H (= full scale) and some applications to set parameters, application parameters will be automatically adapt instrument to measure the environment.4-20 ma is corresponding to the output.

Five, the main features:

1, no blind area, high precision.

2, two wire system technology, it is the differential pressure instruments, magnetostriction, rf admittance, magnetic flap instrument of good alternatives.

3, is not subject to pressure, temperature changes, inert gas, vacuum, dust, steam and other environmental impacts.

4, installation is simple, durable and maintenance free.

5, HART and PROFIBUS - PA communication protocol and the foundation fieldbus, calibration is simple, through digital LCD easy calibration operation, through software GDPF simple configuration Settings and programming.

6, measurement sensitivity, fast refresh.

7, suitable for high temperature working condition, process temperature up to 200 ℃, when high temperature to extend the antenna is used up to 300 ℃.

Six, the technical parameters:

1, the range: line: 30 m/rod: 6 m;

2, wire/rod diameter: 6 mm / ￠￠10 mm;

3, process temperature: 200 ~ 400 ℃;

4, the process pressure: vacuum ~ 400 bar;

5, working frequency: 100 MHZ - 1.8 GHz;

6, repeatability, plus or minus 3 mm;

7, resolution: 1 mm;

8, sampling: echo sampling 54 times/s;

9, the response speed: > 0.2 S (according to the specific use of the case may be);

10, precision: < 0.1%;

11, the output current signal: 4-20 ma;

12, communication interface: HART communication protocol;

13, process connection: G1-1/2, G3/4 flange: (, DN80, DN100, 6;

14, power: 24 VDC (+ / - 10%)

15, ripple voltage: 1 VPP;

16, shell protection grade: IP68;Level of explosion-proof: EXiaIICT6.

Seven, installation instructions:

The following installation instructions applicable to bar type probe and cable type, tubular type probe measurement has nothing to do with the installation.

Location:

1, the distance of tank wall advice 1/6 - a quarter of the tank diameter (at least 300 mm, concrete tank at least 400 mm).

2, do not install in the middle of the metal cans;

3, don't pack the material mouth;

4, when choosing the length of the probe, pay attention to the bottom of the probe from the tank bottom is about more than 30 mm;

5, pay attention to the medium temperature.

Tank obstacles:

1, pay attention to when installation probe at least 200 mm away from the obstacle.

Remove interference:

1, clutter echo suppression: the software can realize the interference echo suppression, so as to achieve the ideal measurement effect;

2, the by-pass pipe and guided wave tube (only applicable to liquid) for viscosity don't play in the 500 CST, can adopt by-pass pipe, guided wave tube or pipe to avoid interference.

Liquid standard installation:

For 500 CST or less and not easy to produce the adhesive medium viscosity, tubular probe is an ideal scheme, its characteristics are as follows:

The reliability of the excellence;

1, can be used in any medium, dielectric constant is greater than or equal to 1.4 measurement has nothing to do with the conductivity of medium;

2, tank obstruction and short tube size does not affect the measurement;

3, than bar type probe can withstand the lateral pressure is high;

4, for the high viscosity of the medium, it is suggested that using bar type probe.

Lie the tank and the installation of vertical tank:

1, tube type probe and bar type probe can be more than 6 meters to 6 meters for measuring distance of tank, can choose 8 mm cable type probe;

2, installation and fixed measuring method with solid powder storehouse;

3, to the distance from the tank wall unlimited, as long as avoiding probe contact tank wall;

4, if the tank obstacles more or too close to the ground rod, please choose tube type probe.

Corrosive medium measurement:

1, if the corrosive medium, can choose lever probe sets a plastic casing was measured.

Eight, the debugging method:

Through debugging in three ways:

1, by displaying the adjustment module PM;

2, through debugging software SOFT;

3, handheld programmer by HART.

Through the SOFT software debugging:

No matter the signal output, 4-20 ma/HART, radar sensors can be through the software debugging.Is instrument with the SOFT software debugging, need a meter CONNECTCAT drives.

Using software debugging, for the radar instrument 24 VDC power up, at the same time connect HART adapter front end with a resistance of 250 ohms.If the one-piece HART resistance (250 ohm internal resistance) of electricity meter, there is no need for additional external resistance, HART adapter can and 4...20 ma line in parallel.

Nine, environmental impact factors are:

1, the influence of the obstacles.

If the launch of the electromagnetic wave instrument comes into contact with the barrier, then you'll get a jamming waveform.If you can't choose other ideal installation location, choose the small beam Angle instrument or using guided wave tube and by-pass pipe installations can be solve the problem.

2, the influence of the transmission medium

(1) the temperature;

(2) pressure;

(3) the transmission medium corrosion resistance;

(4) whether the transmission medium contains steam or dust, etc.;

(5) the volatiles in the environment with crystallization or dust adhesion problems.

To solve the above problem, then we will guarantee, electromagnetic waves or ultrasonic arrived in material surface under test, no big attenuation.Measured on the surface of the material through reflection, get a echo signal.The strength of the echo signal and the measured material surface under state.

1, the dielectric constant of the measured substance or hardness.

The strength of the dielectric constant influence the electromagnetic wave reflection.The echo of the dielectric constant, the greater the stronger.While the hardness is reflection of sound waves.The greater the hardness, the stronger the sound wave reflection.

2, on the surface of the material being tested pile Angle;