32
9
ANNEXES
9.1
WATER QUALITY
In order to protect the water circuit of the Ultracool units, the water to be cooled must have specific
physical/chemical properties so that it is not aggressive. If this water is outside any of the limits listed in the
table below, it can seriously damage some of the materials of the Ultracool unit.
Parameter
Limit values
pH
7 – 8
Total Hardness (TH)
< 150 ppm
Conductivity
50 – 500
µ
S/cm
NH
3
< 2 ppm
Total iron ions (Fe
2+
and Fe
3+
)
< 0.2 ppm
Chloride (Cl
-
)
< 300 ppm
H
2
S
< 0.05 ppm
Solid particles
< 150
µ
m
Ethylene glycol
Max 40%
The Total Hardness is specified in ppm (mg/L) of Ca
2
CO
3
.
Please note that ultra-pure waters like deionized water can also be harmful for some of the materials of the
Ultracool units as they have a conductivity below 50
µ
S/cm.
Do not use automotive antifreeze. Use lab grade ethylene glycol only! Do not use an ethylene glycol
concentration above 40%; this would damage the water pump.
LAUDA Ultracool S.L. will not accept any warranty for any damage caused by water that is out of one or
more of the above limits.