Operating Instructions; Operating Tips - VWR Mini Auto Stirrer Manual De Instrucciones

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PEratINg NstrUCtIoNs
The Mini Auto Stirrer has a hinged support plate that provides automatic on-off control,
thus allowing the speed control setting to remain undisturbed during each batch opera-
tion. The plate activates a motor controlled micro-switch when under the weight of a stir-
ring vessel. The activation weight is approximately 50 grams.
1. getting ready: The stir knob has a built in on-off switch at its extreme counter-
clockwise position. Turn the stir knob to the off position. Plug the power cord into a
properly grounded outlet. Place a vessel with solution and the appropriate acces-
sories in the center of the top plate. This is important for stirring because the stir
bar will be well within the magnetic field.
2. turning unit on: From the off position, turn the stir knob clockwise until a click is
heard, then continue turning until the desired speed is obtained. The stirrer may ini-
tially have to be set at a higher speed to over come friction in the motor and the mate-
rial being stirred. Once this is done, the stirrer will maintain the approximate speed
set for as long as desired.
3. setting speed: Speed adjustments can be made without interrupting stirring by turn-
ing the stir knob clockwise to increase speed or counter-clockwise to decrease
speed.
4. stop stirring: When the stirring is complete, lift the vessel off the hinged top plate.
The motor will shut off. The unit is ready to stir the next sample. Change the speed
setting only when needed.
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oPEratINg tIPs

The stirrer increases speed at a steady rate until the set-point is reached, if the stir bar
is too large or the liquid is too viscous, the stirrer may not reach its set-point. The set-
point speed needs to be reduced.
stirring vessels in oil baths: When stirring a reaction vessel within an oil bath or sim-
ilar set-up, the stirring function will stir up to approximately 2,54cm from the top plate.
The stirring speed will vary according to liquid viscosity, stir bar length an
distance from the top plate. Adjust one or all of these to achieve the desired stirring speed.
ExaMPLE: The closer the reaction vessel is to the top plate the stronger the magnet-
ic connection.
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