Radar submersible capacitive ultrasonic level transmitter price water level transmitter 702

1、Measurement  Principle

• Principle：

High-frequency microwave pulses issued by the guided wave radar propagate along detection components (steel cable or steel rod), met the media to be measured, since the dielectric constant of the mutation, cause reflections, a portion of the pulse energy is reflected back. Transmit pulse and the reflected pulse is proportional to the distance and the time interval measured media.

• Features：

As a result of advanced microprocessor and unique Echo Discovery echo processing technology, guided wave radar level meter can be used in a variety of complex conditions.

Because of the type of process connections and detection components, making Guided Wave Radar Level Meter is suitable for a variety of complex conditions and applications. Such as: high temperature, high pressure and low dielectric constant media.

Pulsed work, guided wave radar level instruments transmit power is very low, can be installed in a variety of metals, non-metallic container, no harm to humans and the environment.

• Explanation：

Guided Wave Radar is a time travel to the principle of measuring instruments, radar run at the speed of light, the running time can be converted into a level signal by electronic components. When the pulse reaches the surface of the material, the pulse is reflected back and is received by the receiving container inside the instrument, the distance the signal is converted to level signals.

Reflected pulse signal along the cable or rod probe type transmit to the instrument electronic circuit parts, the microprocessor processes the signal, identify the microwave pulse echo generated in the material surface. Correct identification of the echo signal are completed the implementation by the pulse software，D, the distance from the material surface and the pulse travel time T is proportional: 

D=C×T/2

Where C is the speed of light

Because the empty distance E is known, the level L is:

L=E-D

 

By entering the empty height of E (= zero), full tank

height F (= hundred) and the application to set

some parameters, application parameters will

automatically adapt the instrument to measure

the environment, corresponding to the 4-20mA

output.

• Measuring range：

--Blind spot is the minimum distance between the top of the highest material surface materials and measurement reference point.

--The bottom of the blind refers to a distance near the very bottom of the cable can not be accurately measured.

--Between the top and bottom of the blind is blind effective measure  distances.

Explanation：

H--- Measuring range

L---Empty distance

B---The top of the blind

E---The minimum distance from the probe

 to the tank wall

Note:

In order to ensure the accuracy of level measurement,

the material should be located between the top and

bottom of the blind the blind.

2、Product  Introduction

702

3、Installation  Guide

Within the measurement range, determined not to come into contact with the cable or rod internal obstacles, Therefore, the installation should be avoided as far as possible the tank facilities, such as: human ladder, limit switches, heating devices, stand etc. Also note that the cable or rod may not intersect with the material during feeding.

• Installation Precautions: 

Highest Level measurement can not enter into the blind; Must be maintained between the instrument and the tank wall a certain distance; When the meter is installed, try to stick with cable or perpendicular to the surface of the measured medium. Meter installation in hazardous areas must comply with state regulations explosion hazardous installation area. Intrinsically safe instrument requires the use of shell with aluminum. Intrinsically safe instrument can be installed in explosion-proof requirements of the occasion, the instrument must be connected to the earth.

Installation position: 

Ø Far away from the discharge port and inlet.

Ø Metal cans in the entire measuring range, not to touch the tank wall and tank bottom.

Ø Recommended meter installed in 1/4 or 1/6 of the silo diameter, and the minimum distance is 1/10 of the tank wall of the measuring range.

Ø Cable type or rod probe the minimum distance from the tank wall ≥300mm.

Ø Bottom of the probe from the tank bottom ≥30mm.

Ø The minimum distance from the probe obstructions ≥200mm.

Ø If the bottom of the container is a cone, you can install a central tank top.

Measurement characteristics of rod radar level:

Ø You can measure any dielectric permittivity of ≥1.8 .

Ø Generally used to measure viscosity ≤500cst, not prone to adhesion medium.

Ø Rod radar maximum range of 6 m.

Ø Instrumentation for steam and foam has a strong penetrating power, the measurement is not affected.

Ø For a lot of foam liquid measurement environment, you should select a single rod guided wave radar level meter measurement.

• Installation Method: 
  

Ø Reasonable meter installation to ensure long-term reliable and accurate measurement 

Guided wave radar level meter adopts thread and flange connection and can be installed on short pipe. The smaller the diameter of the installation pipe, the shorter the pipe length, and the more stable the measurement. When the diameter of the installation short pipe is 2" to 6", the height of the installation short pipe should be ≤200mm. If the short tube is long, it is best to shorten the short tube or lengthen the sensor shielding section.

Ø Installation in short pipe of DN200 or DN250:  

When the guided wave radar is installed on a short tube with a diameter greater than 200mm, the inner wall of the short tube will generate echoes, which may easily cause measurement errors due to the low dielectric constant of the medium. Therefore, for a short pipe with a diameter of 200mm or 250mm, a special flange with a "horn interface" needs to be selected.

Ø Installation Notes on plastic containers:  

Whether cable or rod type, if you want to guided wave radar is working properly, the process of connecting to the metal surface should be. When the guided wave radar mounted on a plastic pot, If the tank top is plastic or other non-conductive material, the instrument needs with metal flanges, the use of threaded connections, to be equipped with a metal plate.

• Installation instructions  
  

The rod probe can be up to 6 meters long. For storage tanks with a measuring distance of more than 6 meters, cable probes are used.

If there are many obstacles in the tank or the probe is easily approached to the sensor, the guided wave-pipe device can be added for measurement.

Pull down force on the rope 

When feeding and discharging, the medium produces a pull-down force on the cable probe. The pull-down force depends on the following factors:

A. The length of the rope                           B. The density of the material

C. The diameter of the storage bin            D. The diameter of the rope

Optimization of interference  

Interference echo suppression: Programming and debugging software can realize the suppression of interference echo, so as to achieve the ideal measurement effect.

For media with a viscosity not greater than 500cst (only for liquids), bypass pipes or  guided wave-pipe can be used to avoid interference.

Installation of low dielectric constant liquid      

For media with dielectric constant greater than 1.3, viscosity ≤ 500cst and not easy to produce adhesion, the guided wave-pipe can be installed for measurement, and the following effects can be achieved:Installation and fixation with the same measurement of solid powder compartment.

• Excellent reliability, high precision

• It can be used for any medium with a dielectric constant ≥1.3, and the measurement has nothing to do with the conductivity of the medium

• Obstacles in the tank and the size of the short pipe do not affect the measurement

Corrosive medium measurement: 

If measuring corrosive media, you can use rod or cable probe sleeve PTFE, PFA sleeve for measurement.

• Special instructions and precautions: 
  

Ø For guided wave radars with too long cables in field use, it is necessary to cut off the excess cables, and the cables cannot be knotted, entangled or attached to other objects.

Ø When cutting the cable, first cut off the power of the instrument, remove the cable, remove the screws, cut from the bottom of the cable, and install the weight after the cut is completed, and then the power can be switched on and the parameters can be reset.

Ø For cable guided wave radar with protective sleeve, when the cable is too long, it must not be intercepted by itself, and it must be returned to the original factory for cutting.

Ø For the instrument installed in the still-pipe, the radar probe must be fixed with an insulating bracket to ensure that the radar probe (rod/cable) and the still-pipe are concentric, otherwise the measurement will be affected by vibration or false echo.

Installation of right and wrong

• Moisture

4、Structure Size（Unit: mm）

• Outer Case size

Ø Cast aluminum shell

Ø Plastic shell

• Product size

• Flange  type

5、The  Electrical  Connection

• Wiring Diagram

Ø 24V  two wire wiring diagram as follows:

Ø 6~24V Modbus-RS485 wiring diagram as follows: 

• Explosion Proof Connection 

The intrinsic safety version sensors (Exia Ⅱc T6) use Alu-die casting housing and filling Silicone rubber sealants internal structure aimed to prevent sparks resulted from circuit failure from leaking out. It is applicable for the continuous level measurement of flammable medium under Exia Ⅱc T6.

A safety barrier FBS-2 must be used together with the intrinsic safety instrument. It is an associated device to this product for the power supply of this product. The main specification is intrinsic safety: Exia ⅡC, voltage of power supply: 24V DC±5%, short-circuit current: 135mA, operating current: 4...20mA.

All cables must be shielded. The max length is 500m for the cable from the barrier to the sensor. Stray capacitor≤0.1μF/Km, stray inductance 1mH/Km. Instrument must be connected to the ground potential. Any unapproved associated device is not allowed to be used.

• Safety  instructions: 

Ø Please observe the local electrical code requirements!

Ø Please comply with local requirements for personnel health and safety regulations.

    All electrical components of instrument operation must be completed by the formal training of professionals.

Ø Please check the instrument nameplate to provide product specifications meet your requirements. Please make sure that the power supply          voltage and instrument nameplate on the requirements.

• Protection Grade:

The instrument fully meet the requirements of protection class IP66/67, make sure the cable head waterproof seal.  As shown below:

How to ensure that the installation meets IP67 requirements:

Make sure that the sealing head is not damaged.

Make sure that the cable is not damaged.

Make sure the cable is used in line with the electrical connection specifications.

Before entering the electrical interface, bend the cable down to ensure that the water does not flow into the housing,  see ①

Please tighten the cable sealing head, see ②

Keep electrical interface with blind unused block after block tight, see ③

6、Instrument debugging

• Three kinds of debugging method:

1) Display / Button (With split display, you need to debug on the split)  

2) Debug through computer software   

3) HART Handheld programmer  

• Display / Button: 

Debug the meter through the 4 buttons on the display screen. The debugging menu has four languages to choose from. The measured value can be read very clearly through the glass window.

Display / Button 

 

① Liquid Crystal Display

② Adjust by button 

PC software debugging：

Connected to PC by HART

 

①  USB interface                      

②  Radar level meter

③ HART converter

④  250Ω resistor

PC software debugging：

HART Handheld programmer  :

 

 

①  HART Handheld programmer

②  Radar level meter

③  250Ω resistor

7、Technical Specification

8、Product  Model  Selection

702