Processing; Paddle Adjustment; After Processing - seward STOMACHER 80 Biowasher Mode D'emploi

4.2

Processing

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The Stomacher 80 Biomaster and 400 Circulator are factory-set with minimal paddle clearance
between the inner face of the door and the fully extended paddles. On the Stomacher
Biowasher and 3500 Thermo, the clearance is set to 10mm. Although suited to a wide range of
applications these settings are by no means suitable for all sample processing and adjustment may
be necessary for your application.
Provision for this adjustment is provided inside the instrument. Since this requires the removal of
the rear cover a competent qualified technician should carry out this work.
4.2.1

Paddle Adjustment.

Switch off and disconnect the instrument from the mains electrical supply. Turn the instrument
over, suitably supporting it to prevent damage. Remove the rear cover and slacken the socket cap
screws holding the motor carriage to the main body via the slotted holes. Do not slacken any of the
screws within the carriage assembly or the motor alignment will be lost. Remove the large hexagon
headed blanking plug (if fitted) from the rear chassis to access the adjusting screw. Turn the
adjusting screw until each paddle just touches the inside face of the door when they are at their
maximum forward stroke position, this can be tested by manually rotating the gearbox output shaft.
If the instrument is run briefly the alternate tapping noise of each paddle touching the door should
just be audible. Take up any backlash in the adjusting screw and turn the screw back one to one and
a quarter turns. This is the minimum clearance setting.
For a greater paddle clearance, each additional backward turn of the adjusting screw increases the
clearance by 1.5mm up to a maximum of 10mm.
When adjustment is complete always re-tighten the socket cap screws, replace the hexagon
headed blanking plug where fitted, and replace the rear cover.
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The Stomacher 3500, 3500 Biowasher and 3500 Thermo are fitted with a neoprene rubber
protective lining to the stomaching chamber to prevent any possibility of the bags being trapped
behind the paddles, especially when using relatively small sample volumes.
Do not attempt to run the instrument without the protective lining in place.
4.3

After Processing

Due to the infinite variety of samples that may be processed in a Stomacher
provide definitive procedures for every application, or give any undertaking, implied or otherwise,
as to the validity of any method used. Seward Limited maintain a library of reference papers
covering practical experience with the Stomacher
available to users upon request.
Page 6 of 33
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STOMACHER
USER INSTRUCTIONS
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system over many years and these details are
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3500, 3500
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it is not possible to
Issue: 3.2