2017-05-12
User Manual
SONO-MIX MINI Version 2_7
Page 11
SONO probe works here as a highpass filter where the higher moisture values are used for building an
average value, and the lower or zero values are filtered out. In the following this function is described
with SONO parameters.
The following parameter setting in mode CA fits a high pass filtering for bridging material gaps.
The Filter Upper-Limit is here deactivated with a value of 20, the Filter Lower-Limit is set to 2%. With
a Lower-Limit Keep-Time of 5 seconds the average value will be frozen for 5 seconds if a single
measurement value is below the limit of 2% of the average value. After 5 seconds the average value
is deleted and a new average value building starts. The Keep-Time function stops if a single
measurement value lies within the Limit values.
2.1.3. Mode CC
– automatic summation of a moisture quantity during one batch process
Simple PLCs are often unable to record moisture measurement values during one longer batch process
with averaging and data storage. Furthermore there are applications without a PLC, where accumulated
moisture values of one batch process should be displayed to the operating staff for a longer time.
Previously available microwave moisture probes on the market show two disadvantages:
1. Such microwave probes need a switching signal from a PLC for starting the averaging of the
probe. This increases the cabling effort.
2. Material gaps during one batch process will lead to zero measurement values which falsify the
accumulated measurement value considerably, recipe errors can occur.
Unlike current microwave probes, SONO probes work in mode CC with automatic summation, where it
is really ensured that the measured material has contact with the probe. This increases the reliability for
the moisture measurement during one complete batch process. The summation is only working if
material fits at the probe. Due to precise moisture measurement also in the lower moisture range,
SONO probes can record, accumulate and store moisture values during a complete batch process
without an external switching or trigger signal. The SONO probe “freezes” the analogue signal as long
as a new batch process starts. So the PLC has time enough to read in the “freezed” moisture value of
Sufficient material for an
accurately moisture
measurement value of e.g.8%
Material gaps over e.g. 3 seconds which must
be bridged for an accurately measurement with
a Lower-Limit Keep-Time of 5 seconds.
