High frequency microwave pulses are coupled on a cable or rod and guided along the probe. The pulse is reflected by the product surface and received by the processing electronics. This electronics evaluates the echo signal and converts it into a level information. All instruments are preset to the ordered probe length. The shortenable cable and rod versions can be adapted to the individual conditions on site.
Applications in liquids
Density fluctuations, steam generation or strong pressure and temperature fluctuations do not influence the measuring result. Also buildup on the probe or the vessel wall do not influence the measurement. An ideal application is level measurement in a bypass tube where even products with dielectric values below 1.6 can be measured reliably. Also connection tubes – bypass tubes have no influence.
Applications in bulk solids
Typical problems in bulk solids such as e.g. dust and noise generation or condensation do not influence the reliability. Also the shape of the material cone or the product properties, e.g. the change from dry to wet sand do not influence the measuring result. Since the instruments are already preadjusted, setup is limited to connection of the sensor.
Related posts:
- Principles of Good Measurement: Radar Level Gauge
- Principles of Good Measurement – Capacitance Sensor
- Principles of Good Measurement – Vibration Level Switches
- Principles of Good Measurement: Ultrasonic Level Transmitters
- Principles of Good Measurement – Conductance Level Switches & Probes
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Hello,
In the above blog it is mentioned that,It is unaffected by Buildp on the Rope or Rod or Cable,Recently one of my friend updated me that he is facing the similar problem.
Application was ,Customer was using Guided wave Radar for measuring Resin whose Viscosity was 300 CPS and Dielectric Constant Value was 3.5 but the Transmitter was showing continously 9 mA.Once customer dismantled the Setup and then cleaned Rod of length 380mm with methanol and installed it again it was working .
Could anybody please elaborate on this Problem ?
Regards,
Venkatesh Gumaste
It would depend on the build-up, format and length of the rod and type of installation. Yours sounds like quite a short length, was it mounted in a tube or a coaxial design? These can be more easily affected by build-up. VEGAFLEX does have a false echo profile, which can be used to map out problematic build-up from filling to a constant height.
Apologies for the delay in replying. It depends on the unit and how it is set up, if build up is anticipated, an increased tolerance to build up can be set. Or a false echo on build up on the rod can also be ‘learnt out’. If build up is on the rod this will cause a small run time error. Build up of a small amount will also affect a dual rod probe or coaxial probe device. In conclusion, if it has good software, it should be able to handle these situations. However, a guided radar however is not the ideal solution for resinous materials, a non contact radar would be much better as this issue would not occur. VEGAPULS 63 has a flush PTFE antenna, and could be a good siolution for this type of material.