KROHNE BM 100A Handbook - Manual (Page 44)

44 Handbook BM 100 A
Solid application notes
Most dry solid applications except powder or flakes with high dielectric constants, such as charcoal
and coal powder, are measured with a Gain of 3. If it is difficult to measure level at a certain point
with the gauge using a Gain from 0 to 2, then an internal tank structure (exposed girder, etc.) is most
likely to be within the electromagnetic pulse field area : the gauge will detect the largest signal and
assume this is the product level.
Interface measurement*
After being switched on, the BM100 A will :
• Identify the closest reflection to the flange above the level threshold (minimum voltage
amplitude set in fct. 1.5.1) as being the level
• Identify the next largest reflection which is above the interface threshold (set in fct. 1.5.4 ) as
being the interface.
Follow instructions given above for Level Threshold modification.
* measurement only possible if the gauge is factory-configured for interface.
1 Initial pulse
2 Flange reflection
3 First largest reflection (level)
4 Second largest reflection
(interface)
5 Level threshold. Set in user
fct. 1.5.1.
6 Measurement not dielectric
constant dependant
7 Measurement dielectric
constant dependant
8 Interface threshold. Set in
user fct. 1.5.4.
Interface measurement when only one product is present in the tank
The gauge assumes that at least 100 mm / 4” of top product is in the tank as soon as
a top product reflection has been detected and/or the short circuit at the end of the
probe is no longer detected. This means that level freezes at a constant 100 mm / 4”
above the indicated interface. Also note however, that the interface level displayed
will be slightly higher than the real value. The gauge will measure the correct interface
and level values once there is at least 100 mm / 4” of top product in the tank.
Default voltage amplitude thresholds for a given Gain : for level and interface
Minimum threshold/ Volts Gain
Level Interface
0 2.59 2.66
1 2.71 2.87
2 2.99 3.34
3 3.62 4.44