IKA RW 28 digital - Manual (Page 7)

7
The motor can be infinitely adjusted via a friction
wheel drive unit but is operated in one position
only. The power output, rotational speed and
torque of the motor are regarded as constant and
are optimized for this operating position. After
the friction wheel drive the motor power output
is transmitted to the output shaft of the stirrer via
either the first or second stage of the subsequent
manually adjustable toothed gear train.
Drive
• Use
For mixing/stirring liquids with low to high vis-
cosity by using various stirring tools.
Intended use: Stand device (Chuck downward).
• Range of use (indoor use only)
- Laboratories - Schools
- Pharmacies - Universities
Correct use
• Unpacking
- Please unpack the device carefully
- In the case of any damage a detailed report must
be sent immediately (post, rail or forwarder)
Unpacking
The speed can be infinitely adjusted between 60
and 1400 rpm 50 Hz; 72 and 1680 rpm 60 Hz.
The machine can be operated continuously and
warms up during operation. The generously pro-
portioned cooling surfaces enable distribution and
transference of heat to be as even as possible.
Useful information
This equipment is suitable for use in all areas except:
- Residential areas
- Areas that are connected directly to a low-voltage
supply network that also supplies residential areas.
The safety of the user cannot be guaranteed:
- If the instrument is operated with accessories
that are not supplied or recommended by the
manufacturer
- If the instrument is operated improperly or contrary
to the manufacturer’s specifications
- If the instrument or the printed circuit board are
modified by third parties.
• Delivery scope
- an RW 28 digital overhead stirrer
- an operating instructions.
- an extension arm
- a hexagonal socket screw
- a hexagon socket offset screw key
- a chuck key
- a warranty card.
The two meters long mains lead makes it possible
to work on stands - even with high glass apparatus
under vapor extraction hoods - without extension
leads.
The precision stirrer shaft is designed as a hollow
shaft to allow the stirrer shanks to be in serted.
Neglecting all losses, the power at the output shaft
during power transmission (conversion) is always as
great as the power output of the motor. The gear
train merely provides rpm and torque conversion,
which can be described in purely theoretical terms
by the characteristic curve plotted in Fig. 2.
Friction wheel wear is kept low by a helical clutch
matched to the gear train. The down-pressure re-
quired at the friction wheel is adjusted by the helical
clutch according to the moment acting on the stirrer
shaft. A low torque results in a low down-pressure;
a high torque results in a high down-pressure.