User's Manual

Page 39 SITRANS LR 400 – INSTRUCTION MANUAL 7ML19985FH04
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Parameters (HART)
3.3.2: Simulate DO (F = End)
Simulation of the digital output signal
Select the applied output value (relay on or relay off).
The parameter function is completed by pressing LEFT so that the digital output again
gives an alarm/limit.
3.4: Sensor Variables
You can read out device-internal data with this parameter group. The displayed values
depend on the respective application. You can access the following data:
3.4.1: Raw Value (for service purposes only)
Distance from the flange to measuring medium
The measured distance from the flange to the surface of the measuring medium.
3.4.2: Echo Amplitude
Measure of quality of reflection
This dimensionless value is an absolute measure of the strength of reflection at the
measuring medium. Its display can be evaluated as follows:
• x > 1: very good
• 1 > x > 0.5: good
• 0.5 > x > 0.05: satisfactory
• x < 0.05: uncertain
3.4.3: S/N Ratio
Signal-to-noise ratio of the measured value in dB
S/N ratio provides a relative measure of the strength of reflection of the measuring
medium in dB. Its display can be evaluated as follows:
• x > 20: very good
• 20 > x > 10: good
• x < 10: satisfactory
Value
Relay on
Relay off
End