IMKO SONO-MIX MINI, SONO-MIX MINI STANDARD, SONO-MIX MINI LD, SONO-MIX MINI XTREM, SONO-MIX Standard User Manual
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I:\publik\TECH_MAN\TRIME-SONO\ENGLISH\SONO-MIX MINI\Manual_SONO-MIX-MINI.docx
SONO-MIX MINI various Versions:
SONO-MIX MINI Standard - for Applications in Concrete Mixer
SONO-MIX MINI LD - for Applications in heterogeneous Materials
SONO-MIX MINI Xtrem - for Applications in Liquids
IMKO Micromodultechnik GmbH Phone: +49 - (0)7243 - 5921 - 0
Am Reutgraben 2 Fax: +49 - (0)7243 - 90856
D - 76275 Ettlingen e-mail: info@imko.de
http: //www.imko.de
User Manual
SONO-MIX MINI
User Manual SONO-MIX MINI Version 2_7 2017-05-12
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User Manual for SONO-MIX MINI
Thank you for buying an IMKO moisture probe.
Please carefully read these instructions in order to achieve best possible results with your
mixer probe SONO-MIX MINI for the in-line moisture measurement in sand, gravel, fresh
concrete or any other material. Should you have any questions or suggestions regarding your
new mixer probe after reading, please do not hesitate to contact our authorised dealers or
IMKO directly. We will gladly help you.
List of Content
1. Instrument Description SONO-MIX MINI .................................................................................. 4
1.1.1. The patented TRIME® TDR-Measuring Method ............................................................. 4
1.1.2. TRIME® compared to other Measuring Methods ........................................................... 4
1.1.3. Areas of Application ....................................................................................................... 4
1.2. Mode of Operation ................................................................................................................. 5
1.2.1. Measurement Values with physically Pre-check, Average Value and Filtering ............. 5
1.2.2. Auto-Correction at Abrasion ........................................................................................... 5
1.2.3. Determination of the Cement Concentration .................................................................. 5
1.2.4. Material Temperature Measurement .............................................................................. 5
1.2.5. Temperature compensation of the internal SONO-electronic ........................................ 6
1.2.6. Analogue Outputs ........................................................................................................... 6
1.2.1. The serial IMP-Bus interface .......................................................................................... 7
1.2.2. The IMP-Bus as a user friendly network system ............................................................ 7
1.2.3. Error Reports and Error Messages ................................................................................ 7
2. Configuration of the Measure Mode ......................................................................................... 8
2.1. Cyclic operation modes CA, CF, CH, CC and CK ................................................................. 8
2.1.1. Average Time in the measurement mode CA and CF ................................................. 10
2.1.2. Filtering at material gaps in mode CA and CF ............................................................. 10
2.1.3. Mode CC – automatic summation of a moisture quantity during one batch process... 11
2.1.4. Mode CH – Automatic Moisture Measurement in one Batch ..................................... 13
2.2. Overview of single modes for different applications ............................................................ 13
2.3. Calibration of SONO-MIX MINI in a mixing plant ................................................................ 14
2.3.1. Shortest expecting mixing times and density effects at partial loads ........................... 17
2.3.2. SONO-MIX to control the water/cement ratio ............................................................... 17
3. Calibration Curves .................................................................................................................... 18
3.1.1. SONO-MIX MINI for measuring Moisture of Sand and Aggregates ............................. 21
3.2. Creating a linear Calibration Curve for a specific Material .................................................. 22
3.2.1. Calculation for a linear 2-point calibration curve .......................................................... 22
3.2.2. Calculation for a linear 1-point calibration curve .......................................................... 23
3.2.3. Calculation for a non-linear calibration curve ............................................................... 23
4. Connectivity to SONO Probes ................................................................................................. 24
4.1. Connection Plug and Plug Pinning ...................................................................................... 25
4.2. Analogue Output 0..10V with a Shunt-Resistor ................................................................... 26
4.3. Connection diagram with SONO-VIEW ............................................................................... 26
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5. Installation of the Probe ............................................................................................................ 27
5.1. Assembly Instructions .......................................................................................................... 27
5.2. Assembly Dimensions .......................................................................................................... 28
5.3. Installation of the SONO-MIX MINI inside a Screw Conveyor ............................................. 29
5.3.1. Installation of the SONO-MIX MINI in a mobile Mixer Truck ........................................ 29
6. Serial Connection to the SM-USB Module from IMKO ........................................................... 30
7. Quick Guide for the Commissioning Software SONO-CONFIG ............................................ 32
7.1.1. Scan of connected SONO probes on the serial interface ............................................. 32
7.1.2. Configuration of serial SONO-interface ........................................................................ 33
7.1.3. Set analogue outputs of the SONO probe .................................................................... 33
7.1.4. Configuration of Measure Mode .................................................................................... 34
7.1.5. Setting the precision of a single value measurement cycle .......................................... 35
7.1.6. Selection of the individual Calibration Curves .............................................................. 36
7.1.8. Test run in the respective Measurement Mode ............................................................ 37
7.1.9. “Measure” Run in Datalogging-Operation ..................................................................... 37
7.1.10. Basic Balancing in Air and Water .............................................................................. 38
7.1.11. Offsetting the material temperature sensor ............................................................... 39
7.1.12. Compensation of the electronic temperature ........................................................... 39
8. TECHNICAL DATA SONO-MIX MINI ......................................................................................... 40
9. Savety Notes .............................................................................................................................. 42
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1. Instrument Description SONO-MIX MINI
1.1.1. The patented TRIME® TDR-Measuring Method
The TDR technology (Time-Domain-Reflectometry) is a radar-based dielectric measuring procedure at
which the transit times of electromagnetic pulses for the measurement of dielectricity constants,
respectively the moisture content are determined.
The SONO-MIX MINI Mixer Probe consists of a high grade steel casing with a wear-resistant sensor
head made of hardened steel and ceramic. An integrated TRIME TDR measuring transducer is
installed into the casing. A high frequency TDR pulse (1GHz), passes along wave guides and
generates an electro-magnetic field around these guides and herewith also in the material
surrounding the probe. Using a new patented measuring method, IMKO has achieved to measure the
transit time of this pulse with a resolution of 1 picosecond (1x10
-12
), consequently determine the
moisture and to provide information in regard to the concrete composition.
The established moisture content, as well as the concrete composition, respectively the temperature,
can either be uploaded directly into a SPC via two analogue outputs 0(4)...20mA or recalled via a
serial interface.
1.1.2. TRIME® compared to other Measuring Methods
In contrary to conventional capacitive or microwave measuring methods, the TRIME® technology (TimeDomain-Reflectometry with Intelligent Micromodule Elements) does not only enable the measuring of
the moisture but also to verify if the cement content specified in a recipe has been complied with. This
means more reliability at the mixing fresh concrete.
TRIME-TDR technology operates in the ideal frequency range between 600MHz and 1,2 GHz.
Capacitive measuring methods (also referred to as Frequency-Domain-Technology) , depending on the
device, operate within a frequency range between 5MHz and 40MHz and are therefore prone to
interference due to disturbance such as the temperature and the mineral contents of the measured
material. Microwave measuring systems operate with high frequencies >2GHz. At these frequencies,
nonlinearities are generated which require very complex compensation. For this reason, microwave
measuring methods are more sensitive in regard to temperature variation.
SONO probes calibrate themselves in the event of abrasion due to a novel and innovative probe design.
This consequently means longer maintenance intervals and, at the same time, more precise
measurement values.
The quality of fresh concrete is the decisive factor for the stability and the durability of concrete
constructions. Hereby, the two parameters moisture and cement content assume a central role as
these determine the consistency and the desired mechanical stability of concrete. The measurement
of these two basic parameters therefore warrant for ideal quality and durability.
SONO-MIX MINI accurately measures both in the dry mixture and in the wet mixture. A "dry mixture"
can e.g. be mixed with residual water varying solids content so that the water content to 70% target is
met. The remaining 30% clean water content can then be dosed with SONO-MIX MINI precisely.
1.1.3. Areas of Application
The SONO-MIX MINI probe is suited for installation into e.g. intensive mixers and chutes and other
plant engineering.
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1.2. Mode of Operation
1.2.1. Measurement Values with physically Pre-check, Average Value and Filtering
SONO probes measure internally at very high cycle rates of 10 kHz and update the measurement value
at a cycle time of 250 milliseconds at the analogue output. In these 250 milliseconds a probe-internal
pre-check of the moisture values is already carried out, i.e. only plausible and physically checked and
pre-averaged single measurement values are be used for the further data processing. This increases
the reliability for the recording of the measured values to a downstream control system significantly. In
the Measurement Mode CS (Cyclic-Successive), an average value is not accumulated and the cycle
time here is 250 milliseconds. In the Measurement Mode CA, CF or CK, not the momentarily
measured individual values are directly issued, but the average value is accumulated via a variable
number of measurements (Average) in order to filter out temporary variations. These variations can be
caused by inhomogeneous moisture distribution in the material surrounding the sensor head. The
delivery scope of the SONO-MIX MINI includes suited parameters for the averaging period and a
universally applicable filter function deployable for currently usual applications. The time for the average
value accumulation, as well as various filter functions, can be adjusted for special applications.
1.2.2. Auto-Correction at Abrasion
Even in the event of abrasion at the probe head of a SONO probe, the automatic measurement
compensation enables significantly longer operating periods without the necessity of recalibration. Many
other probes deployed for the material moisture measurement are equipped with a dielectric screen
(ceramic or plastic plate). If this screen is exposed to wear and a regular recalibration is not conducted,
these probes will provide faulty measurement values as the intensity of the measuring field
subsequently increases due to the wear. At the SONO series with the TRIME TDR radar-based method,
the innovative probe design ensures for the automatic correction of the sensor in case of changes to the
dielectric screen caused by abrasion. This consequently means continuous reliability and longer
maintenance intervals at the SONO probes.
1.2.3. Determination of the Cement Concentration
With the radar-based TRIME measurement method, it is now possible for the first time, not only to
measure the moisture, but also to provide information regarding the conductivity, respectively the
cement content, the expansion rate or the composition of a special material. Hereby, the attenuation of
the radar pulse in the measured volume fraction of the material, e.g. fresh concrete, is determined. This
novel and innovative technology measures the same amount of material as with the moisture
measurement and delivers a radar-based conductance value (EC-TRIME Radar-based-Conductivity) in
dS/m. EC-TRIME is a characteristic value which is determined in dependency of the cement
concentration, respectively the water/cement ratio and is issued as an unscaled value. The EC-TRIME
measurement range of the SONO-MIX MINI is 0..50dS/m.
1.2.4. Material Temperature Measurement
A temperature sensor is installed into the SONO-probe which establishes the casing temperature 3mm
beneath the sensor surface. The temperature can optionally be issued at the analogue output2. As the
TRIME electronics operates with a power of approximately 1.5 W, the probe casing does slightly heat
up. A measurement of the material temperature is therefore only possible to a certain degree. The
material temperature can be determined after an external calibration and compensation of the sensor
self-heating. The offset of the measured temperature value can be adjusted with help of the program
SONO-CONFIG.
Despite SONO probes show a generally low temperature drift, it could be necessary to compensate a
temperature drift in special applications. SONO probes offer two possibilities for temperature
compensation.
1.2.5. Temperature compensation for the measured material
Water and special materials like oil fruits and others, can show a dependency of the dielectric
permittivity when using SONO probes at high temperature ranges. The dielectric permittivity is the raw
parameter for measuring water content with SONO probes. If special materials show a very special
temperature drift, e.g. in lower temperatures a higher drift than in higher temperatures, than it could be
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necessary to make a more elaborate temperature compensation. Therefore it is necessary to measure
in parallel the material temperature with the temperature sensor which is placed inside the SONO
probe. Normally this is related with high efforts in laboratory works. SONO probes offer the possibility to
set special temperature compensation parameters t0 to t5 for every calibration curve Cal1 of Cal15 (see
chapter “Selection of the individual calibration curve”). Please contact IMKO should you need any
assistance in this area.
1.2.6. Temperature compensation of the internal SONO-electronic
With this method of temperature compensation, a possible temperature drift of the SONO-electronic can
be compensated. Because the SONO-electronic shows a generally low temperature drift, SONO probes
are presetted at delivery for standard ambient conditions with the parameter TempComp=0.2.
Dependent on SONO probe type, this parameter TempComp can be adjusted for higher temperature
ranges (up to 120°C for special version) to values up to TempComp=0.75. But it is to consider that it is
necessary to make a Basic-Balancing of the SONO probe in air and water, if the parameter TempComp
is changed to another value as TempComp=0.2. The parameter TempComp can be changed with the
software tool SONO-CONFIG, in the menu "Calibration" and the window "Electronic-Temperature-
Compensation".
Attention: When changing the TempComp parameter, a new basic balancing of the
SONO probe is necessary!
1.2.7. Analogue Outputs
The measurement values are issued as a current signal via the analogue output. With the help of the
service program SONO-CONFIG, the SONO probe can be set to the two versions for 0..20mA or
4..20mA. Furthermore, it is also possible to variably adjust the moisture dynamic range e.g. to 0-10%, 0-
20% or 0-30%. For a 0-10V DC voltage output, a 500R resistor can be installed in order to reach a
0..10V output.
Analogue Output 1: Moisture in % (0…20%, variable adjustable)
Analogue Output 2: Conductivity (EC-TRIME) or optionally the temperature.
In addition, there is also the option to split the analogue output 2 into two ranges: into
4..11mA for the temperature and 12..20mA for the conductivity. The analogue output
two hereby changes over into an adjustable one-second cycle between these two
(current) measurement windows.
For the analogue outputs 1 and 2 there are thus two adjustable options:
Analog Output: (two possible selections)
0..20mA 4..20mA
For very special PLC applications, the current output can be inverted into:
20mA...0mA or 20mA…4mA
Analogue Output Channel 1 and 2: The two analogue outputs of the SONO probe
can be adjusted into one to four possible selections.
1. Moist, Temp
Analogue output 1 for moisture, output 2 for
material temperature.
2. Moist, Conduct
Analogue output 1 for moisture, output 2 for
conductivity in ranges of 0..20dS/mS or
50dS/m
3. Moist,
Temp/Conductivity
Analogue output 1 for moisture, output 2 for
both, temperature and conductivity (ECTRIME) with an automatic current-window
change in cycles of 5 seconds.
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4. Moist /
MoistSTdDev
Analogue output 1 for moisture, output 2 for
the standard deviation based on the single
moisture values. This function is useful in e.g.
fluid bed drier for air volume control.
Adjustment for the Measurement Ranges
For analogue output 1 and 2 the moisture dynamic range and temperature dynamic
range can be variably adjusted. The moisture dynamic range should not exceed 100%
Moisture Range: Temp. Range:
Maximum: e.g. 20 for sand (Set in %) Maximum: 70 °C
Minimum: 0 Minimum: 0 °C
Conductivity Range: 0..20dS/m or 0…50dS/m
Dependent on probe type and moisture range, SONO probes can measure pore water
conductivities (EC-TRIME) in ranges of 5dS/m up to 50dS/m.
1.2.1. The serial IMP-Bus interface
SONO-probes are equipped with a standard RS485 as well as the IMP-Bus interface to set and readout
individual parameters or measurement values. An easy to implement data transfer protocol enables the
connection of several sensors/probes at the RS485-Interface. In addition, SONO-probes can be directly
connected via the module SM-USB or the display module SONO-VIEW to the USB port of a PC, in
order to adjust individual measuring parameters or conduct calibrations.
Please consider: The initial default setting of the serial interface is pre-setted for the IMP-Bus. To
operate with the RS485 inside the SONO-probe, it is necessary to switch and activate the RS485
interface with help of the modul SM-USB or SONO-VIEW.
In the Support area of IMKO´s homepage www.imko.de we publish the transmission protocol of the
SONO-probes.
1.2.2. The IMP-Bus as a user friendly network system
With external power supply on site for the SONO probes, a simple 2-wire cable can be used for the
networking. By use of 4-wire cables, several probes can be also supplied with power.
Standard RS485-interfaces cause very often problems! The RS485 is usually not galvanically
isolated and therefore raises the danger of mass grindings or interferences which can lead to
considerably security problems. An RS485 network needs shielded and twisted pair cables, especially
for long distances. Depending on the topology of the network, it is necessary to place 100Ohm
termination resistors at sensitive locations. In practice this means considerable specialist effort and
insurmountable problems.
The robust IMP-Bus ensures security. SONO-probes have in parallel to the standard RS485 interface
the robust galvanically isolated IMP-Bus which means increased safety. The serial data line is isolated
from the probe´s power supply and the complete sensor network is therefore independent from single
ground potentials and different grid phases. Furthermore the IMP-Bus transmit its data packets not as
voltage signals, but rather as current signals which also works at already existing longer cables. A
special shielded cable is not necessary and also stub lines are no problem.
1.2.3. Error Reports and Error Messages
SONO probes are very fault-tolerant. This enables failure-free operation. Error messages can be
recalled via the serial interface.
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2. Configuration of the Measure Mode
The configuration of SONO- probe is preset in the factory before delivery. A process-related later
optimisation of this device-internal setting is possible with the help of the service program SONO-
CONFIG. For all activities regarding parameter setting and calibration the probe can be directly
connected via the serial interface to the PC with SM-USB-Module or the SONO-VIEW display module
which are available from IMKO.
The following settings of SONO probes can be amended with the service program SONO-CONFIG:
Measurement-Mode and Parameters:
Measurement Mode A-On-Request (only in network operation for the retrieval of measurement
values via the serial interface).
Measurement Mode C Cyclic:
SONO-VARIO is supplied ex-factory with suited parameters in Mode CH for measuring
moisture of sand and gravel. For other applications, mode CA could be usable. Up to 6 different
modes can be adjusted:
Mode CS: (Cyclic-Successive) For very short measuring processes (e.g. 2…10 seconds)
without floating average and without filter functions, with internal up to 100 measurements per
second and a cycle time of 250 milliseconds at the analogue output. Measurement mode CS
can also be used for getting raw data from the SONO-probe without averaging and filtering.
Mode CA: (Cyclic-Average-Filter) For relative short measuring processes with continual
average value, filtering and an accuracy of up to 0.1%
Mode CF: (Cyclic-Float-Average) for continual average value with filtering and an accuracy of
up to 0.1% for very slowly measuring processes, e.g. in fluidized bed dryers, conveyor belts,
etc.
Mode CK: (Cyclic-Kalman-Filter with Boost) Standard setting for SONO-MIX for use in fresh
concrete mixer with continual average value with special dynamic Kalman filtering and an
accuracy of up to 0.1%.
Mode CC: (Cyclic Cumulated) with automatic summation of a moisture quantity during one
batch process.
Mode CH: (Cyclic Hold) similar to Mode CC but without summation.
Mode CH is recommended for applications in the construction industry. If the SONO-
probe is installed under a silo flap, Mode CH can measure moisture when batch cycles are very
short, down to 2 seconds. Mode CH executes an automatic filtering, e.g. if dripping water
occurs.
Precision of a single TDR radar pulse measurement (see in chapter „Software tool SONO-CONFIG“
under point „Setting the precision of a single value measurement”.
Each of these settings will be preserved after shut down of the probe and is therefore stored on a
permanent basis.
2.1. Cyclic operation modes CA, CF, CH, CC and CK
For the cyclic modes the SONO probes are supplied ex-factory with suited parameters for the averaging
time and with a universally deployable filter function suited for most currently applications.
The setting options and special functions of SONO probes depicted in this chapter are only rarely
required. It is necessary to take into consideration that the modification of the settings or the realisation
of these special functions may lead to faulty operation of the probe!
For applications with non-continuous material flow, there is the option to optimise the control of the
measurement process via the adjustable filter values Filter-Lower-Limit, Filter-Upper-Limit and the time
constant No-Material-Keep-Time. The continual/floating averaging can be set with the parameter
Average-Time.
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Parameters in the
Measurement Mode CA, CF,
CC, CH and CK
Function
Average-Time
Standard Setting: 2s
Setting Range: 1…20
Unit: Seconds
CA/CF: Time (in seconds) for the generation of the average value
can be set with this parameter.
CC/CH/CK: Setting of the time for calculation of the trend or
expectation value for the Boost & Offset function.
Filter-Upper-Limit-Offset
Standard Setting: 25%
Setting Range: 1….20
Unit: % Absolut
CA/CC/CF/CH/CK: Too high measurement values generated due
to metal wipers or blades are filtered out. The offset value in % is
added to the dynamically calculated upper limit.
Filter-Lower-Limit-Offset
Standard Setting: 25%
Setting Range: 1.….20!
Unit: % Absolut
CA/CC/CF/CH/CK: Too low measurement values generated due
to insufficient material at the probe head are filtered out. The
offset value in % is subtracted from the dynamically calculated
lower limit with the negative sign.
Upper-Limit-Keep-Time
Standard Setting: 10
Setting Range: 1...100
Unit: % Absolut
CA/CC/CF/CH/CK: The maximum duration (in seconds) of the
filter function for Upper-Limit-failures (too high measurement
values) can be set with this parameter.
Lower-Limit-Keep-Time
Standard Setting: 10
Setting Range: 1...100s
Unit: Seconds
CA/CC/CF/CH/CK: The maximum duration (in seconds) of the
filter function for Lower-Limit-failures (too low measurement
values) for longer-lasting "material gaps", ie the time where no
material is located on the probe´s surface can be bridged.
Moisture Threshold
(start threshold in %-moisture)
Standard Setting: 0.1%
Setting Range: 0….100%
Unit: % Absolut
CA/CF/CK: inactive
CC/CH: The accumulation of moisture values starts above the
„Moisture Threshold“ and from here the analogue signal is
outputted. The accumulation pauses and will be frozen if the
moisture level is below the threshold value. The No-Material-
Delay time starts and material gaps (disturbance) can be
eliminated.
No-Material-Delay
(period time)
Standard Setting: 10s
Setting Range: 1….100s
Unit: Seconds
CA/CF/CK: inactive
CC/CH: The accumulation stopps if the moisture value is below
the Moisture Threshold. The accumulation pauses for the period
of the setted delay time and will be frozen if the moisture level is
below the threshold value. The SONO probes starts again in a
new batch with a new accumulation after the setted time span of
the “No-Material-Delay” is completely exceeded.
Boost
Standard Setting: 35nn
Setting Range: 1….100nn
Unit: without unit!
CA/CF: inactive
CC/CH/CK: Defines, how strong single measurement values are
weighted dependent on deviation to the current expected average
value. With e.g. Boost=35, a single measurement value is
weighted with only 65% (100-35) for a new average value.
Offset
Standard Setting: 0.5%
Setting Range: 0 ….5%
Unit: % Absolut
CA/CF: inactive
CC/CH/CK: Non-linearities in the process can be compensated
by higher weighting of higher values. Can be used e.g. in fluid bed
dryers or under silo flaps where non-linearities can occur due to
changes in the material density during process. “Offset” works
together with the parameter “Average-time”.
Weight
Standard Setting: 5 values
Setting Range: 0 …..50
Unit: Measurement Values
CA/CF/CK: inactive
CH: Smoothing factor for analog output setting. This parameter
influences the reaction/response time with factor 3. E.g. 15 values
responds to a reaction time of 15/3=5 seconds.
CK: The reaction/response time works nearly 1:1.
E.g. 15 values responds to a reaction time of 15 seconds.
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Invalid Measure Count
Standard Setting: 2 values
Setting Range: 0….. 10
Unit: Measurement Values
with 3 single values per second.
CA/CF/CK: inactive
CC/CH: Number of discarded (poor) measurement values after
the start of a new batch, when „No-Material-Delay“ has triggered.
The first measurement values will be rejected, e.g. due to dripping
water.
Moisture Std. Deviation Count
Standard Setting: 5 values
Setting Range: 0….. 20
Unit: Measurement Values
with 3 single values per second.
CA/CC/CF/CH/CK: If the parameters Temperature or EC-TRIME
(RbC) are not needed, the analogue output 2 can be setted tot he
mode Moist/Moist Std. Deviation. In this mode the standard
deviation of all single moisture values can be outputted. With this
function the homogeneity of the single measurement values can
be determined and it is possible to control a regulating process,
e.g. pressure regulation.
Quick und Quick-Precision
With Meas Time (no. values)
Unit: without unit!
CA/CC/CF/CH/CK/CS: Recommended is Quick Precision with
Meas Time=2 where the TDR pulse is detected precisely. For still
a little better accuracies, Meas Time can be increased, however
the single measurement cycle is increased by 60 milliseconds per
step (e.g. from 280ms to 340ms). Older SONO probe versions do
not have this Quick Precision function!
2.1.1. Average Time in the measurement mode CA and CF
SONO probes establishes every 200 milliseconds a new single measurement value which is
incorporated into the continual averaging and issues the respective average value in this timing cycle at
the analogue output. The averaging time therefore accords to the “memory” of the SONO probe. The
longer this time is selected, the more inert is the reaction rate, if differently moist material passes the
probe. A longer averaging time results in a more stable measurement value. This should in particular be
taken into consideration, if the SONO probe is deployed in different applications in order to compensate
measurement value variations due to differently moist materials.
At the point of time of delivery, the Average Time is set to 4 seconds. This value has proven itself to be
useful for many types of applications. At applications which require a faster reaction rate, a smaller
value can be set. Should the display be too “unstable”, it is recommended to select a higher value.
2.1.2. Filtering at material gaps in mode CA and CF
A SONO probe is able to identify, if temporarily no or less material is at the probe head and can filter out
such inaccurate measurement values (Filter-Lower-Limit). Particular attention should be directed at
those time periods in which the measurement area of the probe is only partially filled with material for a
longer time, i.e. the material (sand) temporarily no longer completely covers the probe head. During
these periods (Lower-Limit-Keep-Time), the probe would establish a value that is too low. The Lower-
Limit-Keep-Time sets the maximum possible time where the probe could determine inaccurate (too
low) measurement values.
Furthermore, the passing or wiping of the probe head with metal blades or wipers can lead to the
establishment of too high measurement values (Filter-Upper-Limit). The Upper-Limit-Keep-Time sets
the maximum possible time where the probe would determine inaccurate (too high) measurement
values.
Using a complex algorithm, SONO probes are able to filter out such faulty individual measurement
values. The standard settings in the Measurement Mode CA and CF for the filter functions depicted in
the following have proven themselves to be useful for many applications and should only be altered for
special applications.
It is appropriate to bridge material gaps in mode CA with Upper- and Lower-Limit Offsets and KeepTime. For example the Lower-Limit Offset could be adjusted with 2% with a Lower-Limit Keep-Time of 5
seconds. If the SONO probe determines a moisture value which is 2% below the average moisture
value with e.g. 8%, than the average moisture value will be frozen at this value during the Lower-Limit
Keep-Time of 5 seconds. In this way the material gap can be bridged. This powerful function inside the
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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.
User Manual SONO-MIX MINI Version 2_7 2017-05-12
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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 will start.
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.
Please note: If the PLC already accumulates single moisture values in higher cycle rates, than an
additional automatic summation of a moisture quantity inside the SONO-probe during one batch
process will produce errors. Here mode CS is recommended.
How can the mode CC be used, if the SONO probe cannot detect the „moisture threshold“ by
itself, e.g. above a conveyor belt if there is constant material covering above the probe head
over a longer time: In this case, a short interrupt of the probe´s power supply, e.g. for about 0.5
seconds with the help of a relay contact of the PLC, can restart the SONO probe at the beginning of the
material transport. After this short interrupt the SONO probe starts immediately with the summarizing
and averaging.
Please note: It should be noted that no material sticks on the probes surface. Otherwise the moisture
zero point detection of the probe will be shifted up and the probe would not be detect a moisture low
value below the “Moisture-Threshold”.
Time chart for mode CC
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2.1.4. Mode CH – Automatic Moisture Measurement in one Batch
Mode CH can be used for applications in the construction industry. If the SONO-probe is installed under
a silo flap, Mode CH can measure moisture when batch cycles are very short, down to 5 seconds (and
perhaps shorter). Mode CH executes an automatic filtering with Invalid Measure Count, e.g. if dripping
water occurs or for filtering out the first false measurements after opening the silo flap. The
measurement cycle starts if the probe detects the Moisture Threshold value and freeze the analogue
output value until the next cycle.
2.2. Overview of single modes for different applications
The following table gives an overview about possible parameter settings in different modes:
Application/
Installation
and specific
Parameters
Sand/
Gravel
under a
silo flap
Above a
conveyor
belt
Inside a
mixer
Inside a
fluid bed
dryer
Gene-
rally
simple
appli-
cations
in a screw
conveyor
with
filtering
options
due to
metal
spiral
At the
end of a
screw
conveyor
Long
term
process
Operating
Mode
CH
CH
CK
CK
CA
CK
CF
AverageTime
2 2 5 5 10
10
30
FilterUpper-Limit
Offset
inactiv
100
inactiv
100
inactiv
100
inactiv
100
e.g. 20
inactiv
100
e.g. 20
FilterLower-Limit
Offset
inactiv
100
inactiv
100
inactiv
100
inactiv
100
e.g. 10
inactiv
100
e.g. 5
UpperLimit-KeepTime
inactiv
10
inactiv
10
inactiv
10
inactiv
10
e.g. 10
inactiv
10
e.g. 10
LowerLimit-KeepTime
inactiv
10
inactiv
10
inactiv
10
inactiv
10
e.g. 10
inactiv
10
e.g. 10
Moisture
Threshold
0.1
0.1
0.1
0.1 - 0.1
-
No-MaterialDelay
10
10
10
10 - inactiv
-
Boost
35
35
20
20 - 20 - Offset
0.5
0.5 1 1 - 1 - Weight
5 5 25
25 - 50
-
Invalid
Measure
Count
2 2 inactiv
inactiv
-
inactiv
-
For very difficult applications, where it is not certain, which mode is the best, we recommend to select
mode CA with averaging time = 1 second. With help of the software SONO-CONFIG a data record can
be stored directly during process conditions. After forwarding this data set to IMKO, we would be
pleased to be at your disposal for finding the best suitable working mode.
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2.3. Calibration of SONO-MIX MINI in a mixing plant
SONO-MIX MINI is delivered with a raw calibration function which is far higher than the real moisture
values (kiln dried values) of a sand/gravel or fresh concrete mixture. The reason is that SONO-MIX use
a powerful modified filter algorithm, which would work incorrect at Zero-values (division by zero results
in infinite). Therefore it is necessary with SONO-MIX, (as well as with all other moisture probes), to
make a recipe specific calibration with the PLC in the mixing plant. Another reason for this calibration is
that every mixer type has another behaviour concerning the raw density of the mixed material.
In practice, a mixer moisture probe has to be calibrated with two points in the mixing plant. The first
calibration point should be relatively dry, e.g. at 2 to 3% gravimetric moisture. The second point should
be in a range which matches the maximum moisture value in practice, e.g. 5%. The closely together
these both moisture-values1 and 2 are, the higher could be the measurement error due to the
reference measurement, especially at moisture values which are beyond of these two points or not
between these two points!
Following process can be recommended:
1. Record measurement values in the PLC for a dry mixture of one cubic meter, i.e. the mixture
has a relative low water content. It is recommended to average the values of the PLC over the
last 5 seconds of the dry mixing time. In this example a measurement value of 8126 has been
recorded with the PLC:
SONO-MIX
Measurement
values
(current signal
from 4…20mA)
Measurement
value in a PC
(in % moisture)
Digit Value of
A/D-Converter
PLC
without unit from
0 to max. 32768
digits
Water
content
Measurement
values with dry
mixture
5.968 mA
3.2
8126
This is the
Dry-value-A/D
2. Add water manually into the dryer mixture, e.g. 20.0 liter water. The added and measured
water content is later used for the calculation of the c1-Sensitivity of the SONO-MIX for this
recipe. When the mixture has a stable consistency, than record the measurement values with
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