Lightning Audio 7532 manual Mounting calibration with VU, Function group mounting calibr

7532 Commissioning

6.5Mounting calibration with VU 331

6.5.1Function group "mounting calibr." (03)

⇒

– + E

Function "tank gauging" (030)

⇒

– + E

Using this function, you can either enter a dip table or carry out an auto-correction.

Function "auto-correction" (031)

⇒

– + E

When measuring levels with radar systems, so-called "multipath reflections" can affect the level signal giving rise to serious measuring errors. "Multipath reflections" also include radar beams which are received by the radar system, which have not been reflected directly by the medium surface. They may reach the antenna via the basin wall and the medium surface. This phenomenon is particularly noticeable with devices mounted near to walls, as soon as the conical radar beam strikes the basin wall.

The 7500 RTG can automatically discover and correct measuring errors due to this "multiple path" propagation. This is because it uses two independent sets of information when evaluating reflection signals:

•Firstly, it evaluates the amplitude of the reflected energy using the so-called envelope curve system.

•Secondly, it evaluates the phase of the reflected energy.

The decisive factor for a constant output signal is to assign the phase values to the associated level values. This assignment is ensured using a correspondence table (index correction table). The 7500 RTG learns this for the specific application after installation (learning period).

Therefore, after mounting the device, and after completing the basic calibration, a history reset must be performed (enter "yes" in the "history reset" (009) function in the "basic setup " (00) function group).

Do not switch off the radar system during filling and emptying operations during the teach-in phase. Switching off when there are only negligible level changes produces no error.

"Caution!

During the learning period, fast filling/emptying or turbulent surfaces can result in switching off and on the phase evaluation. Subsequently observed measurement errors will disappear as soon as tank levels come back to areas measured by 7500 RTG previously with activated phase evaluation. If the observed measurement errors are curetted by dip table entries, the 7500 RTG will take care of these corrections and automatically adjust the index correction table. Do NOT correct any settings in the basic calibration or the extended calibration.

Note!

Immediately after installation, the 7500 RTG measures with the specified mm-accuracy. Until the level range has been completely covered by the medium (setting up the

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