Dynalab CB162 - Manual (Page 3)

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spillages are attended to promptly. In any case, spillages of alkali, phosphoric acid
and hydrofluoric acid MUST be removed immediately as these chemicals can attack
and damage the glass ceramic. Ensure that the appropriate safety precautions are
observed.
During cleaning and general operation take care not to scratch the surface of the
top plate as this could result in subsequent thermal breakage.
WARNING: A ceramic top which is scratched, chipped, chemically etched or
damaged must not be used.
Metal top units:
The metal top plate should be cleaned using a damp cloth and a mild detergent
solution.
Cleaning is made easier if spillages are attended to promptly. In any case, spillages of
acids and alkalis MUST be removed immediately as these chemicals can attack and
damage the the surface of the aluminium alloy. Ensure that the appropriate safety
precautions are observed.
Preparation of 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.
Accessory
A rod is available to support apparatus used with the instrument. The instrument is
equipped with a fitting on the rear to accept the support rod - catalogue number
SR1, (see figure 2). To fit the rod to your instrument, first isolate from the mains
supply and allow to cool. Then simply screw the threaded end of the support rod
into the fitting on the rear of the instrument.
Heating
CB160, CB162, SB160, SB162
The control knob labelled “Heat” on the front panel controls the heat output and
hence the plate temperature. It is graduated with an approximate temperature scale.
This scale refers to the temperature of the top plate and not to the temperature of
the contents of the vessel being heated, When the heat is switched on an amber
pilot light illuminates, (see figure 1).
When the surface becomes too hot to touch a red warning light on the front panel
will begin to flash, (see figure 1). This will continue to flash while the plate
temperature is above 70°C so long as the unit remains connected to the electricity
supply.
WARNING: The top surface of the instrument may be HOT In free air a surface
temperature of 450°C can be achieved on the ceramic top models and 325°C on the
metal top models. Do not leave heaters switched on when not in use.
Stirring
CB161, CB162, SB161, SB162
The control knob labelled “Stir” on the front panel controls the stirrer speed. When
switched on an amber pilot light illuminates, (see figure 1).
The knob is graduated with an arbitrary 1-9 scale. Turning the knob to a higher
number increases the stirrer speed.
Safety Advice
❖ Do not use the instrument to heat inflammable liquids
❖ Never lift or carry the instrument until it has been switched off and allowed to
cool for at least 30 minutes. The hot warning light will give guidance.
❖ The unit should be carried using both hands with the fingers under the side
edges.
❖ Never move or carry the 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.
Cleaning and Care
Before attempting cleaning:-
Ensure that the top is cool
Disconnect from the mains electricity supply.
The metal casing should be cleaned using a damp cloth and a mild detergent
solution.
Ceramic top units:
A damp cloth will normally remove most types of contamination. For more difficult
stains a domestic cream cleanser is recommended. Cleaning is made easier if
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