Siemens sitrans PROBE LU - Device and Sensor Lifetime Parameters

7ML19985JB02 SITRANS Probe LU (PROFIBUS PA) – INSTRUCTION MANUAL Page 57
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F: Profile structure
How the LTB works:
1. The sensor technology block selects the proper echo. For an explanation of sensor
technology, please refer to
Appendix A: Technical References on page 35.
The sensor value (in sensor units) is checked to see if it is within its measuring limits.
If the limit is exceeded, this results in a Bad status and the error message Failure in
measurement. The sensor value is stored in Sensor Value.
The analog signal from the sensor is transformed into a digital signal.
A Sensor Offset (default 0) provides compensation if necessary for changes in the
sensor.
2. Level Calibration is a linear transfer function that converts a sensor value to a level
value. The level value is used for volume calculation, if that function is enabled.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Low Calibration Point Sensor Value High Calibration Point
Level
High Level Point
Low Level Point
Calibration
Level Value
High Level
Point
(default: 100%)
Sensor Reference Point
(transducer face)
Sensor Value
Low Level
Point
(default: 0%)
Secondary Value 1
Low
Calibration
Point
High
Calibration
Point
Distance 1 or 2
(SV2 or SV3)
Tan k reference
point
Near Range
Level
Level Offset
Sensor Offset
Far
Range
Far
Range