Mettler Toledo SevenCompact S230 Conductivity Mode D'emploi page 32

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G = GT * f
T25
If another reference temperature is used, for example 20 °C, the conductivity corrected to 25 °C is
divid e d by 1.116 (see f
●
GT = (GT · f
20
Conductivity measurements of natural water can only be performed at temperatures ranging from 0
°C to 36 °C. Otherwise, the warning message "Temp. out of nLF correction range" appears.
Pure water
Similar to non-linear correction for natural water a different type of non-linear correction is used for
ultra-pure and pure water. The values are compensated in the range from 0.005 to 5.00 μS/cm at
tem p er a t ures (0-50°C) that differ from the reference temperature (25°C). This could for example be
when checking the pure or ultra-pure water production equipment, or when checking if the clean-
ing-in-progress procedure for which ultra-pure water has been used had led to the removal of all
soluble substances. Due to the high influence of CO2 from the air, we strongly suggest to use the
flow-through-cell for this type of measurements.
●
Conductivity measurements using the pure water compensation mode can only be performed
at temperatures ranging from 0 °C to 50 °C. Otherwise, the warning message "Temp. out of
pure water range" appears.
●
In case the conductivity reading exceeds the upper limit of 5.00 μS/cm in the mode pure war-
er, the compensation will resemble a linear compensation mode with = 2.00 %/°C.
TDS factor
TDS (Total dissolved solids) is calculated by multiplying the conductivity value with the TDS factor.
A factor between 0.40 and 1.00 can be entered.
Conductivity Unit
One can choose the following conductivity units for display in the conductivity mode:
●
μS/cm & mS/cm
The instrument will switch automatically between μS/cm and mS/cm depending on the mea s ure-
ment value. This unit is the standard for most conductivity measurements.
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μS/m & mS/m
The instrument will switch automatically between μS/m and mS/m depending on the measurement
val u e. This unit is for example used for determination of the conductivity of ethanol according to
the ABNT / ABR 10547 method.
Conductivity Ash
Conductivity Ash (%) is an important parameter that reflects the content of soluble inorganic salts
in refined sugar or raw sugar/melasses. These soluble inorganic impurities directly affect the pu-
rity of the sugar. This meter can measure conductivity ash according to the following two ICUMSA
meth o ds (see "Appendix: Conductivity ash methods"):
●
28 g / 100 g solution (refined sugar - ICUMSA GS2/3-17)
●
5 g / 100 mL solution (raw sugar – ICUMSA GS1/3/4/7/8-13)
The instrument will directly convert the measured conductivity to conductivity ash % according to
the selected method.
The user has the possibility to enter the conductivity of the used water for preparing the sugar solu-
tions in μS/cm (0.0 to 100.0 μS/cm). This value is then used for correcting the measured con d uc-
tiv i t y ash values according to the formulae given in "Appendix: Conductivity ash methods".
Conductivity ash measurements are only possible in the temperature range from 15°C to 25°C
30 Menus and settings
25
for 20.0 °C)
25
) / 1.116
25