Hotplates and stirrers

Q: Hotplates : How fast do the hotplates heat up?

A: The ceramic hotplate CB160 heats to its maximum temperature, 450°C, within 8 minutes. The aluminium hotplates SB160 and SD160 heat to 325°C in about 5 minutes.

Q: Hotplates : What is the temperature uniformity of the hotplate?

A: Digitally controlled hotplates SD300 and SD500 have a temperature range of about 10°C across the plate surface. Analogue versions have a simpler control circuitry so the variation will be greater.

Q: Overhead Stirrers : I need to stir a large volume of viscous solution and a magnetic stirrer is not very effective. What other options do I have?

A: The Stuart overhead stirrers are designed for effective mixing of large volumes or viscous liquids. There are three models depending on the sample volume and viscosity with the heavy duty SS30 capable of stirring solutions of up to 40,000 mPas (thick oil or honey).

Q: Stirrer Hotplates : I need to control the temperature of the solution rather than the hotplate. What are the options?

A: The models CD162 and SD162 have a built in temperature controller and are supplied with a PTFE coated probe which, when immersed in the liquid sample can control the temperature within +/-0.5°C. The models SC162 and CC162 can be used with the SCT1 temperature controller to the same accuracy. With both options, the maximum temperature to which the sample can be controlled is 200°C. The SCT1 can also be used as a digital thermometer up to 325°C.

Q: Stirrer Hotplates : What is the advantage of a ceramic top over an aluminium top?

A: Glass ceramic tops have excellent chemical and temperature resistance. Hot plate stirrers with ceramic tops are capable of reaching temperatures up to 450°C with very fast heat up times. The surface is also easy to clean and the white surface ensures good visibility of colour changes.

Q: Stirrers : What is the maximum volume of sample I can stir with a magnetic stirrer?

A: The CB161 and SB161 stirrers have a maximum stirring capacity of 15 litres. This is based on a sample of water in a 20 litre beaker. The volume will be less for more viscous solutions and will also depend on the vessel in which the liquid is being stirred. If a larger capacity is required, then the SB301 is capable of stirring up to 30 litres of water.