WD62

Working principle

Guided Wave Radar Level Transmitter works on the principle of time and travel (TDR).

Radar wave travels at the velocity of light. The flying time is converted into level signal via the electroniccomponents.

The probe emits high frequency wave pulse which travels along a cable probe or a rod probe.

When the wave pulse reaches the medium surface, it will be reflected and received by the receiver, and thenthe distance signal will be converted into level signals.

   Installation guide                                                                                                                           

Mounting position

 Away from the medium inlet and outlet as far as possible.

 For metal tanks and plastic tanks, it is not allowed for probe totouch the inner wall along its whole length. Do not mount thelevel transmitter in the middle of a metal tank.

 It is suggested to mount the instrument at the 1/4 of a tankdiameter.

 For cable probe or rod probe, the probe must be kept away frominner wall at least 300mm, the suggested distance between theprobe and the inner wall is ≥500mm.

 The distance from probe bottom end to the bottom of a tank isapprox. 30mm.

 Probe should keep away from any obstacle inside a tank at lease200mm.

 When bottom of a tank is tapered, the transmitter can bemounted in the middle of tank top. So it can measure the level ofmedium to the bottom of the tank.

This drawing on right is for the installation ofa guided wave radar transmitter with rodprobe, mainly for liquid level measurement.

 It can measure any liquid which dielectric constant is ≥1.9.

 Generally it can measure a liquid which viscosity is ≦500cst andis not adhesive.

 The maximum measuring range of rod probe guided wave radarcan be up to 6m.

 Measurement will not be affected when there is steam and foamin a tank.

 Coaxial tube radar can be used for liquids with low dielectricconstant to ensure the exact measurement.

 It can measure any liquid which dielectric constant is ≥1.6.

 Generally it can measure a liquid which viscosity is ≦500cst andnot adhesive.

 The maximum measuring range of coaxial probe radar can be upto 6 m.

 Measurement will not be affected when there is steam and foamin a tank.

 Properly installation of the transmitter can make correct andreliable measurement.

 The transmitter can be mounted with thread, the installationheight should be higher than 100mm. It can also be mounted ona short pipe with the diameter of 2”~6”.The installation height ofthe short pipe should be ≦100mm. When the instrument has tobe mounted on a longer short pipe, the cable probe should befixed at the bottom end of it, or use the centering frame to fix theprobe so as to avoid it from contacting the short pipe end.

 Mounting on a short pipe DN200 or DN250.

 When the transmitter has to be mounted in a short pipe whichdiameter is >200mm, there will be echoes inside the short pipewall, this will cause the error especially when the medium haslow dielectric constant. Therefore, a special flange with “horn” isrequired for the short pipe which diameter is 200mm or 250mm.

 Installation on a plastic tank.

 Note: whichever cable probe or rod probe, the connectionsurface must be metal if want to keep the transmitter normalwork. When a transmitter is mounted on a plastic tank, metalflange is required for the transmitter. When the processconnection is thread, a metal board is required.

 Distance between probe and tank wall It is suggested the min. distance a transmitter probe and wall side is 1/6~1/4 (at least >300mm, for the concentrate tank at least 400mm) of the tankdiameter, the distance between probe bottom and tank bottom is >30mm.

 Keep anything inside a tank away from the micro wave sensing components

 Radar is not allowed to be mounted above the medium inlet

Calibration

 PC with software GWSOFT

 A HART hand-held communicator

 Display setting module GWPM

Calibration with PC and software GWSOFT

All radar transmitters can be debugged by software via a PC. A transmitter drive “connect cat” isrequired when using the GWSOFT software for the debugging.

Radar transmitter requires 24V DC when debugging, at the same time to connect a 250ohmresistance in the front of the HART adapter. If it is an integrated HART resistance (integratedresistance is 250ohm), then the additional outside resistance is not required, HART adapter can beconnected in parallel to 4~20mA wire.

Radar transmitter requires 24VDC during the debugging, at the same time it connects a resistance of250ohm before the HART adapter. If it is an integrated HART resistance, the additional outsideresistance will not be required. HART adapter can be connected in parallel with 4~20mA wire.

Calibration with a hand-held HART communicator

Calibration with GWPM

GWPM programmer has 4 buttons and 1 LCD display. It can display the calibration menu and parameterssetting.

Structure dimensions (unit: mm)

Flange size table (DIN PN16)

General parameters