User Manual
6
OPERATION
64
OPTIWAVE 7400-24 C
www.krohne.com 12/2015 - 4004901901 - MA OPTIWAVE7400-24 R01 fr
2.4.2 RANGE I This menu item sets the limits of the output
current range to 1 of the 2 available options:
standard limits (4...20 mA) or NAMUR
NE 43-compliant limits (3.8...20.5 mA). It
also tells the device what to do if an error
occurs. if you set RANGE I to 4-20/22E
4-20/22E4-20/22E
4-20/22E and
an error occurs (e.g. the tank is too full, ...),
the device output current will change to an
error value of 22 mA . If you set RANGE I to
4-20
4-204-20
4-20 and the device senses a measurement
error, the value will stop at the last correct
measurement.
4-20, 4-20/22E, 4-
20/3.6E, 3.8-20.5/22E,
3.8-20.5/3.6E
4-20/3.6E
2.4.3 SCALE 4mA This gives a measurement value to 4 mA. min.-max: 2
1
2.4.4 SCALE 20mA This gives a measurement value to 20 mA. min.-max: 2
1
2.4.5 ERROR DELAY The time after which the current output
changes to an error value. The error value
shows that there is a measurement error.
mn=minutes and s=seconds.
0 s, 10 s, 20 s, 30 s, 1 mn,
2 mn, 5 mn,15 mn
0s
2.5.0 APPLICATION
2.5.1 TANK TYPE The conditions in which the device is used. If
the surface of the product is flat, select
"Storage". If the surface of the product is
disturbed, select "Process". If the surface of
the product is agitated with vortexes and
foam, select "Agitator".
Storage, Process,
Agitator
Process
2.5.2 STILLWELL D. The inner diameter of the stilling well. If the
device is installed in a stilling well or has a
Wave-Guide antenna, enter the diameter.
The device will use this data if you set 2.3.4
STILLWELL EN. to "Yes". This menu item is
not shown if you set 2.3.4 STILLWELL EN. to
"No".
min-max: 22...999 mm /
0.9...39.3¨
1
2.5.3 TRACING VEL. Maximum tracking velocity. This value must
agree with the maximum rate of change of
the level of the liquid in the tank.
min-max:
0.1…10.0 m/min
0.5 m/min
2.5.4 MEASUR.MODE The device uses the dielectric constant (ε
r
)
of the tank contents to monitor level. In
direct mode (if the dielectric constant is
high), the level signal is a reflection on the
surface of the tank contents. If the dielectric
constant is low, the device uses TBF mode.
The device in TBF mode uses the radar
reflection on the bottom of the tank (the
signal goes through the tank contents). The
tank must have a flat bottom for the device
to operate correctly in TBF mode. This
menu item is set by default to "Direct" for
tank contents with an ε
r
>1.8. If ε
r
is very low
(<1.6), use "TBF Full". If ε
r
is low (ε
r
=
1.5...1.7), use "TBF Partial" mode. "TBF
Partial" is an automatic mode that lets the
device make a selection between "Direct
mode and "TBF" mode. If you use "TBF Full"
or "TBF Partial", enter the dielectric
constant in menu item 2.5.3 Er PRODUCT.
Refer also to "Measuring principle" on page
87.
Direct, TBF Partial, TBF
Full
Direct
Menu
No.
Function Function description Selection list Default