IMKO SONO-VARIO LD, Руководство пользователя

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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.
1.4.3. Mode CC
– automatic summation of a moisture quantity during one batch process
Simple PLCs are often unable to record moisture measurement values during one 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 three 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. Time delays can occur during the summation time with a trigger signal which leads to
measurement errors. This is particularly disadvantageous for small batches, recipe errors can
occur.
3. 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 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 the batch. For
applications without a PLC the “freezed” signal of the SONO probe can be used for displaying the
moisture value to a simple 7-segment unit as long as a new batch process starts.
With the parameter Moisture Threshold the SONO probe can be configured to the start moisture
level where the summation starts automatically. Due to an automatic recalibration of SONO probes, it
is ensured that the zero point will be precisely controlled. The start level could be variably set
dependent to the plant. Recommended is a level with e.g. 0.5% to 1%.
With the parameter No-Material-Delay a time range can be set, where the SONO probe is again
ready to start a new batch process. Are there short material gaps during a batch process which are
shorter than the “No-Material-Delay”, with no material at the probes surface, then the SONO probe
pauses shortly with the summation.
Is the pause greater as the “No-Material-Delay” then the probe is
ready to start a new batch process.