Thermo Scientific LevelPRO, User Manual

Page: 15 / 128

Thermo Scientific LevelPRO User Manual xiii
Quick Setup
The procedures described in this section assume you will access the menu items
directly.
Setup
The minimum data needed to make a level measurement is listed below.
–
Detector Length
– Minimum Span
– Maximum Span
– Level Type
Standardization
Before the detector can convert the measured radiation value to a measurement of the
process level in the vessel, the amount of radiation arriving at the detector must be
measured for at least two known levels of the process material (tank empty and tank
full). Normally the standardization measurement is performed with the vessel empty
(process level at or below the bottom of the detector) when the maximum amount of
radiation reaches the detector. The standardization value establishes a reference
measurement point that can be easily repeated latter to maintain the calibration of the
detector. Once the standardization (0%) and calibration (100%) measurements are
complete, the detector uses these values to convert the measured radiation into an
indication of the process level. This level indication may be adequate for many
applications.
Calibration
There are up to ten calibration points that can be performed on the process.
The ten calibration points allow you to have calibration points in the region of interest,
and can accurately achieve a good level reading in that region. Any buildup on the
vessel walls can also be calibrated to achieve accurate level readings. Remember that
each Cal Point must be higher than the previous Cal Point (i.e., Point 2 may only be
calculated after Point 1).