User's Manual

7ML19985FH01 SITRANS LR 400 – INSTRUCTION MANUAL DRAFT Page 31
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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 function is ended after pressing so that the digital output again gives an alarm/
limit.
3.4: Sensor Variables
You can read out device-internal data with this function. 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
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