JUMO dTRANS CR 02, Operating Manual, Page: 101 / 120

101
16 Appendix
Ultra-pure water per Ph. Eur.
The limit comparators of the instrument switch, depending on the
corresponding configuration, according to the limit valued of the European
Pharmacopeia (Ph. Eur.) for purified water.
Ph. Eur. warning alarm
The Ph. Eur. warning alarm switches before the water quality reaches the set
limit value.
This parameter (0 to 100) is used to set the distance as a percentage (relative
to the active limit value) to be maintained from the USP limit.
TDS
Display/control with the unit ppm.
The specific TDS factor can also be entered in this mode.
TDS (Total Dissolved Solids, also commonly referred to in Germany as
filtrate dry residue (Filtrattrockenrückstand).
This value is important in areas such as groundwater analysis and power
plants.
The value is also used in evaluating drinking water quality (for example in the
USA, Arab and Asian countries).
Various organizations have published limit values on this topic.
- WHO (World Health Organization) <1000mg/l
- USEPA (United States Environmental Protection Agency) <500mg/l
Standardized determination is performed gravimetrically, i.e.:
- Filter sample
- Evaporate filtrate
- Weigh residue
A conductivity measurement is used for the online measurement. A single time
is sufficient to determine the conversion factor. It corresponds to the ratio of
the conductivity value of the water to the value of the gravimetrically
determined filtrate dry residue (TDS). The factor moves within the range from
0.55 to 1.0. A typical value for drinking water is about 0.67.
With modern instruments, this factor can be entered individually to achieve the
most accurate measurement possible.
Temperature
°C
Max. conductivity
µS/cm
0 0.6
10 0.9
15 1.0
20 1.1
25 1.3
30 1.4
35 1.5
40 1.7
45 1.8
50 1.9