User's Manual

LX-80 User Manual
Page 12 of 32
4.1. Measurement through materials (containers)
Geolux LX-80 instrument uses microwave radar for distance measurement and as
microwave signal is passing through most of dielectric (non-conductive) materials very
easy it is possible to mount radar outside of the container to measure level of the liquid
inside of the container. Dielectric materials used in industry and buildings: ABS, PVC,
Nylon, Teflon, Polycarbonate, Plexiglas, Polyamide, Polypropylene etc. are very suitable
for microwave level measurement from out of the containers. In such application
instrument can be placed above the container and pointed to the liquid inside the container
below the sensor. Care should be taken to avoid reflections, vibrations and all other
negative effects like in all other applications.
4.2. Rain and wind
Geolux LX-80 instrument has integrated internal software filters to filter out effects
of rain, fog or wind for radar distance sensor. These filters however have some limitations.
Majority of measurement inaccuracies caused by environmental factors can be solved by
proper sensor installation.
For rain and snow suppression, the most effective solution is to mount the radar so that
it points directly at water. As rain or snow fall, they affect the water surface, so it is not
as reflective as usually, thus reducing the SNR. However, our devices are tested and
calibrated in a way, so they detect the surface even under heavy rainfall.
Influence of the wind on the accuracy is in most cases small and can be neglected.
The only exception is strong wind as it will create surface waves and turbulences which
can be detected as a shift in level. As mentioned above, length of radar filter can be
adjusted to compensate for this.
4.3. Interference and multiple radars
Distance measurement radar is operating in W-band from 77 GHz to 81 GHz with
linear frequency modulation, modulating signal continuously in the mentioned frequency
range. To get interference between two or more sensors it will be required to keep central
frequencies very precise just like in surface velocity radar and additionally timing
synchronization of radar should be kept in range of 25 ns to each other. Such