Heidolph RotaChill - Manual (Page 34)

110-509 HD/EN 33
Reservoir Fluids
No matter what bath fluid is selected, it must be chemically compatible with the reservoir and the
materials in your Circulator. It must also be suitable for the desired temperature range.
WARNING : Do not use a flammable liquid as a bath fluid as a fire hazard may result.
WARNING: Always use fluids that satisfy safety, health, and equipment compatibility requirements.
For optimum temperature stability, the fluid’s viscosity should be 50 centistokes (cSt) or less at its lowest
operating temperature. This permits good fluid circulation and minimizes heating from the pump.
WARNING: For temperatures from 10°C to 90°C, distilled water is recommended. For temperatures
below 10°C, a mixture of laboratory grade ethylene glycol and water should be used (mixing ratio
1:1). Do not use deionized water.
WARNING: DO NOT USE THE FOLLOWING LIQUIDS:
• Automotive antifreeze with additives**
• Hard tap water**
• Deionized water with a specific resistance > 1 meg ohm
• Any flammable fluids
• Concentrations of acids or bases
• Solutions with halides: chlorides, fluorides, bromides, iodides or sulfur
• Bleach (Sodium Hypochlorite)
• Solutions with chromates or chromium salts
• Glycerine
• Syltherm fluids
** At temperatures above 40°C, additives or mineral deposits can adhere to the heater. If deposits are allowed
to build up, the heater may overheat and fail. Higher temperatures and higher concentrations of additives
will hasten deposit build up.
Application Notes
At a fluid's low temperature extreme:
• The presence of ice or slush adversely affects temperature stability.
• A viscosity above 10 centistokes adversely affects temperature uniformity.
• A high fluid viscosity and high pump speed adds heat to the fluid being pumped.
At a fluid's temperature above ambient without refrigeration:
• If your set point temperature is less than 15°C above the ambient temperature, the
viscosity of the fluid should be 10 centistokes or less to minimize friction heating of the fluid.
• Heat loss should be encouraged by uncovering the fluid and lowering the pump speed.