Grant Instruments SBB Aqua Plus - Manual (Page 16)

29825 Ver. 2 - July 2010 71W SUB, JB & SBB Aqua Plus
Page 15 Operating Manual
www.grant.co.uk
Models Capacity (L) Current Rating (A)
120V 230V
SBB Aqua 5 Plus 5 6 11
SBB Aqua 12 Plus 12 7 11
SBB Aqua 18 Plus 18 9 11
SBB Aqua 26 Plus 26 9 11
SUB Aqua Plus bath performance
Temperature range 5°C above ambient to 99°C
Display (also used for setting) 10.0 to 99.0°C in steps of 0.1°C
Temperature stability at 37°C ± 0.2°C
JB Aqua Plus bath performance
Temperature range 5°C above ambient to 98°C
Setting scale 10 to 98°C in 2°C graduations
Temperature stability at 37°C ± 1.0°C
SBB Aqua Plus bath performance
Temperature range 100°C only
7.0 Technical Tips
7.1
Which water should you use in your bath?
For the long-term reliability of water baths it is important to use oxygenated water that is
free from ions and minerals that can cause corrosion of stainless steel. We recommend
the use of distilled water and de-ionised water from modern ion exchange systems that
do not use salt back flushing to regenerate the ion-exchange cartridges.
Stainless steel is protected from corrosion by a layer of chromium oxide. If the layer is
damaged, oxygen present in water can reform the oxide layer. If the water is still or de-
oxygenated, and the oxide layer is damaged, ions can corrode the stainless steel tank. If
a water bath has been unused for some time, or water boiled, we recommend changing
to fresh distilled water or correct de-ionised water.
Water normally contains calcium or magnesium ions. De-ionised water has most ions
removed as indicated by its conductivity level; the purer the water the lower the
conductivity. It is important to use only de-ionised water from an ion exchange system
with replaceable cartridges. Do not use de-ionised water generated from an ion-
exchange system that incorporates a salt back-flush system to regenerate the ion-
exchange resin as this can leave sodium ions that are very corrosive to stainless steel.
7.2
How to prevent rust in water baths
Most Grant tanks, as well as immersed parts, are made from type 304 stainless steel, an
extremely versatile general purpose grade of stainless steel. It is the excellent forming
characteristic that has made this grade dominant in the manufacture of laboratory and
industrial water baths, as well as domestic sinks and saucepans. Type 304 stainless
steel is highly suitable for applications where hygiene is important; it exhibits good heat
resistance and excellent resistance to corrosion.