Do you need to immerse the samples within a tank?
Consider the working area that you require. The minimum and maximum liquid depths you need, and the capacity of the water bath.
What cool down time is required?
Calculate the cool-down time required according to the following formula
t (mins) = (V x T x K) /60 x W
W= average cooling power
V = Total system liquid volume
T = temperature difference °C
K = liquid heat capacity (J/L/°C)
Do you need to control the temperature form an external source?
1. Consider the pump requirement. Liquid flow rate is critical in order to maintain adequate exchange of heat within the external system. Factors which cause a pressure drop are height, length, pipe bore and the number and angle of bends within the system. To maintain sufficient flow in a highly restricted system, a high pressure pump is required. The integral pumps are in the thermostats like the Grant Optima range of thermostatic heaters and are satisfactory for most laboratory applications.
2. Consider whether you need to control the temperature within the external apparatus. For external temperature control consider a unit like the Grant Optima TX150 of the TXF200 controller and an external temperature probe.
For more information on the full range of chilled and refrigerated Grant Water Baths and the Optima range please complete the contact form below.