Endress+Hauser Solitrend MMP20, Руководство по эксплуатации

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Commissioning fresh concrete measurement Solitrend MMP20 (Option D)
38 Hauser
The SWZ probe measures the same parts of water as the kiln-drying method:
• The free water in the concrete mix which enters into the calculation of the w/c-ratio.
This water is the actual value that is sought when using the SWZ probe.
• A share of the core water , water that is absorbed by the aggregates. The SWZ probe can
only measure a share (approx. 1/3) of the core water here. The core water can be
5 to 35 l/m³ depending on the type of rock. This (correction) value is represented in the
G-Set parameter (approx. 2/3 of the core water), depending on the formulation and
rock. The G-Set value is typically –10 l/m³ assuming a typical core water value of 15 l/m³
of water. These –10 l/m³ are automatically subtracted from the measurement in the
device so that the reading in the device matches the effective water content.
• Additives that behave like water are also measured by the SWZ probe. This must be
taken into consideration.
9.6 Air voids, glass fibers and steel fibers
Air voids and glass fibers reduce the concrete density and therefore the moisture.
The SWZ probe does not react to either air voids or glass fibers. As a result, the water
content it displays for concrete with air voids or glass fibers is somewhat too high.
Depending on the proportion of air voids or glass fibers, the reading shown on the device
can be 5 to 10 l/m³ too high. We recommend reducing the G-Set parameter in the device
by –5 to –10 l/m³, depending on the concrete formulation.
In the case of concrete with steel fibers, the water content displayed by the device is also
somewhat too high due to the steel content. Here too it is recommended to reduce this by
–5 to –10 l/m³ in the device using the G-Set parameter.