Endress+Hauser Solitrend MMP20, Руководство по эксплуатации

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Commissioning fresh concrete measurement Solitrend MMP20 (Option D)
32 Hauser
9 Commissioning fresh concrete measurement
NOTICE
During the measurement process, there should never be any metal parts in the
vicinity of the probe head, as metal can affect the measuring field of the probe. Fresh
concrete should always be measured in a plastic bucket, as this rules out any
influence of metal on the measurement. The probe surface must be clean and free
from any residue. No concrete should be caked to the surface of the probe.
‣
Clean the probe with a wire brush if necessary
• To obtain a representative value for the material mix, take at least 5 individual
measurements (see Measurement cycle for SWZ probe).
• In the case of concretes that tend to bleed, taking a higher number of individual
measurements increases the accuracy and ensures a more representative value.
• Large gravel pieces directly at the surface of the probe can affect a reading; a lower
water content is measured, for example.
• Incorrectly mixed concretes are difficult to measure with the probe.
The standard deviation StdDev displayed by the handheld device reflects the quality of the
reading. If the StdDev value is >0.5, the concrete mix is too heterogeneous; more single
measurements are required. At least 6 single measurements should be taken and a StdDev
of 0.1 to 0.5 should be displayed before you can stop taking single measurements and
accept the measured value as the final result.
The operation of the handheld device with the individual keys, probe connection, charger,
etc. is described in detail in the manual. The following section only explains individual
actions with the LCD display and the keys.
To be able to display the exact water content, the system must be set beforehand to
the "formulation characteristic" and to the variety of concrete with the rock type.
The device can be set to the characteristic of the concrete formulation with the "fine",
"coarse", "normal" or "special" setting in the CHAR parameter (see the "Settings and
measurement" section).
It is possible to fine-tune to the variety of concrete with the rock type using the G-Set
parameter. If the G-Set value has a positive sign, the set value is automatically added or
subtracted during the measurement. If a water content that deviates from the reference
continues to be displayed, the G-Set value would need to be reduced, for example from –10
to –8. The exact G-Set value which has to be factored in for the concrete variety with the
rock type (location) and entered into the device can be checked or determined in two ways:
• By comparing the measurements of the SWZ probe with several correct target values for
the water content of the concrete
• By comparing the measurements of the SWZ probe with several correct values of a
laboratory method (e.g. kiln drying)
9.1 Procedure
9.1.1
1.
Switching on the handheld device
Pressing the Enter key for long ( >1 s) switches on the device in the "CHANGE"
formulation menu. Pressing the Enter key again for longer (only in this measuring
window!) switches the device off again. The device switches off automatically after 10 min
if it is not operated during this time (this time can be shortened or increased to up to
20 min in the "Auto-Power-Off" menu item).
9.1.2
2.
Changing the raw density, CHAR parameter and G-Set
The raw density of the concrete to be measured must be entered before the water content
is measured. In addition, the characteristic of the concrete formulation must be set to "fine,