Environmental Express StirBase - Manual (Page 5)

800.745.8218 / 843.576.1147 / www.environmentalexpress.com Environmental Express • 3
StirBaseTM: Operation and Instruction Manual Setup and Operation
Setup
StirBlock Stirrer Installation
Caution: Operating the StirBase TM in close proximity of ferromagnetic or aluminum
materials, or both, is not recommended.
We recommend that the StirBase
TM Stirrer be installed as far away from
ferromagnetic material as possible. The closer and larger the magnetic material is
to the StirBase
TM Stirrer, the greater the torque that is required and the slower the
maximum speed will be.
Placement on a sturdy bench top or table is also recommended. Thick aluminum
table tops or robot decks, as well as racks or holders, should be avoided. Although
aluminum is not magnetic it will cause a drag on the magnetic field due to eddy
currents being formed when magnetic flux lines pass through it. A large mass of
aluminum will cause a significant drag and result in undue strain on the motor.
This strain causes the motor to overheat (>60oC) which could burn out the motor.
This is not covered under Environmental Express’ warranty for this product.
Operation
Operating the Controller
The controller must be located outside of a fume hood in an ambient clean air
environment.
The maximum speed is set at the factory to 2150 RPM with no load and the
speed control knob set to 100. Because the load (magnetic resistance) will directly
affect speed, it is not possible to accurately relate the dial setting to speed (RPM)
in every situation. In general, the speed control knob has to be set to at least 20
to overcome inertia. If the stirrer is placed near a ferromagnetic object, a higher
dial setting is required to overcome inertia. Once the optimal stirring speed has
been determined, note the position and leave the speed control knob set to that
position.
The control unit for the stirrer has an ON/OFF power switch and a speed control
knob. Place the power switch in the ON position (toggle up) and adjust the speed
control knob to change the operating speed of the StirBase
TM Stirrer. The speed
control for the Stirrer is designed to control the speed and to gradually take the
unit from the OFF position to the set speed in a gradual acceleration. The speed
control knob should not be used to stop the motion of the Tumble Stirrers. To stop
the Tumble Stirrer always flip the power switch to the OFF position (toggle down).
Operating the StirBase TM
The optimal operating speed of the StirBase TM Stirrer is dependent upon the
particular application to be used and needs to be empirically determined. Factors
to consider in determining optimal stir speed are the fragility of the objects being
stirred; size, shape, and composition of the test tube, vial, or bottle (polypropylene
or polystyrene); depth of the microplate wells; volume and viscosity of the liquid;
and the type of stir disc or bar used.
Caution: Operating the StirBase TM for extended periods of time or with
challenging loads is not recommended.