Total Lab Supplies offer a wide range of hotplates and
hotplate/stirrers. The Stuart range is
well known in laboratories and they offer some good advice on the operation of
these units.
- Do not use hotplates to heat inflammable liquids.
- Never lift or carry a hotplate until it has been switched
off and allowed to cool for at least 30 minutes. A hot warning light will give
guidance.
- A hotplate should be carried using both hands with the
fingers under the side edges.
- Never move or carry a unit with containers on the top plate
or while still connected to the mains supply.
- There is a danger of liquid spillage if containers are
over-filled and stirred at high speed. Always build stirrer speed slowly and
never stir more rapidly than necessary
- NEVER place a cold glass vessel onto a hotplate which is
already hot.
When using a ceramic hotplates like the Stuart UC152 at
temperatures over 180ºC, the base of any equipment used must not make contact
with the ceramic plate outside the Hot Zone or heated plate area.
The use of a Stuart SCT1 temperature controller allows accurate
temperature control of aqueous and oil based samples in the laboratory and can
be used in two different modes, as a precise temperature controller from 20 to
200°C or as a digital thermometer from -4 to 325°C.
Care when preparing media
Take particular care when heating liquids having a high
viscosity. Viscous liquids can act as thermal insulators and can cause thermal
breakage of the glassware. This is very important with media solutions as the
viscosity will usually increase as the temperature rises.
- Check that the stirring action is
sufficient to agitate the whole of the liquid.
Unstirred areas in the liquid can result in uneven heat transfer and
“hot spots” in the glassware. This can induce thermal stress and so cause
failure.
- Check the stirring action regularly
to ensure that it remains adequate as the viscosity of the solution increases.
- Always use the largest magnetic
follower possible and if necessary, use a mechanical overhead stirrer.
- Do not use glass vessels with thick
walls, e.g. Pyrex Heavy Duty Ware or standard beakers and flasks having
capacities of 5 litres or greater.
- NEVER heat glass
bottles on a hotplate.
- Ensure that the heat
is built up slowly to avoid localised overheating.
- Ensure the glassware
is completely free from scratches or other defects.
- Place the hotplate in a tray large
enough to contain the liquid in the event of glassware failure.
- Wear the appropriate
safety clothing e.g. gloves, goggles, protective apron etc.
Following these guidelines using a stirrer/hotplate should
ensure trouble free use.
For all
your hotplate/stirrer needs please get in touch
