2017-05-12 User Manual SONO-MIX MINI Version 2_7
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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
