Stirring Operating Instructions; Operating Tips - VWR Professional Serie Manual De Instrucciones

S O I
TIRRING PERATING NSTRUCTIONS
The micro-processor controlled ramping feature slowly increases speed until
the set-point is reached. This feature helps to avoid splashing, improves
magnetic coupling and provides excellent low end control. The
micro-processor also monitors and regulates the stirring speed, sensing your
requirements whether you're stirring an aqueous, viscous or semi-solid
solution.
Initial stirring speed may exceed set speed if the following conditions exist:
1. The stirrer is set at a low speed and the stirrer has not been operated for
a extended period of time.
2. The stirrer is set at a low speed and it is the stirrer's initial use.
1. Getting ready:
a. Plug power cord into a properly grounded outlet.
b. Place a vessel with solution and the appropriate accessories in the
center of the top plate. This is important because the spin bar will be
well within the magnetic field.
c. Press the standby button to move the unit from standby mode. The
speed and time displays will illuminate.
2. Setting speed:
a. Press the up/down arrows below the speed display until you reach the
desired speed.
b. To start stirring function, press the on/off button below the speed
display.
c. The indicator light below the speed display will illuminate to indicate
the stirring function is in use.
d. Speed adjustments can be made without interrupting stirring by using
the up/down arrows below the speed display.
e. To stop stirring function, press the on/off button below the speed
display.
3. Set timed mode:
a. Press the up/down arrows below the time display until you reach the
desired time.
b. When the unit is started, by pressing the on/off button below the
temperature or speed display, the unit will run for the selected time.
There are audible beeps to indicate the time down function is
complete. The unit will shut off automatically. To repeat for the same
11 time, simply depress the on/off button again.
c. To interrupt an automatic timing cycle before it is completed, press the
on/off button below the temperature or speed display.
4. Set time to continuous mode:
a. Set timer to zero (0) using the up/down arrows below time display.
b. When the unit is started, by pressing the on/off button below the
temperature or speed display, the time display will show actual running
time.
c. To stop, press the on/off button below the temperature or speed
display.
Stir protection for Hotplate-Stirrers:
If stirrer motor stops or fails, the unit will automatically shut down the
heater.

OPERATING TIPS

The stirrer increases speed at a steady rate until the set-point is reached, if
the spin 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. The magnetic
strength of stir bars reduce over time and may need to be replaced.
Stirring vessels in oil baths:
When heating and stirring a reaction vessel within an oil bath or similar
set-up, the stirring function will stir up to approximately one 2,54cm from
the top plate. The stirring speed will vary according to liquid viscosity, spin
bar length and 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
magnetic connection.