User's Manual

7ML19985JE03 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 133
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D: Technical Reference
Sensor Mode
This parameter controls the input. Depending on the reference point used, the
measurement reports either Level, Space, or Distance. By default Sensor Mode is set to
Level.
You also have the option to put the device out of service, in which case the device
defaults to Fail-safe mode, and the reported level depends on the device type. A standard
device reports the last valid reading, and a NAMUR NE 43-compliant device reports the
user-defined value for Material Level (3.58 mA by default).
Current Output Function
Current Output Function (2.6.1.) controls the mA output and applies any relevant scaling.
By default it is set to Level. Other options are Space, Distance., and Volume. (The device
can carry out a volume calculation only after a vessel shape has been specified.)
When a volume application type is chosen, Sensor Mode remains as Level and the mA
Output is automatically converted to Volume.
To view the mA reading in the secondary region of the LCD, press
on the handheld
programmer.
Operation Description Reference point
NO
SERVICE
Measurement and associated loop
current not being updated. Device
defaults to Fail-safe mode
a)
.
a)
See Fail-safe Mode on page 134.
LEVEL Distance to material surface
Low Calibration Point (pro-
cess empty level)
SPACE Distance to material surface
High Calibration Point (pro-
cess full level)
DISTANCE Distance to material surface Sensor Reference Point
Level Space Distance
Distance
Space
Level
20 mA
100%
4 mA
0%
High
Cal.
Pt.
4 mA
0%
20 mA
100%
4 mA
0%
20 mA
100%
Sensor
reference
point
Low
Cal.
Pt