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- From : Braun-Knecht-Heiman
Co., Catalog No. 40 Laboratory Instruments Apparatus Supplies,
Braun-Knecht-Heiman Co. (1940) pp. 31-3.
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- Courtesy of the VWR Scientific
Corporation
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LABORATORY BALANCES
CHRISTIAN BECKER ANALYTICAL BALANCES
MODERN industry demands modern
equipment. A little calculation shows that the average chemist
spends a significant part his working time at the Balance. Chemists
are frequently seen in the laboratory waiting for their turn
at a Balance, holding up important work to make a necessary weighing.
The necessity, therefore, of a rapid, convenient and accurate
Balance is evident.
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- Recognition of the importance of the Balance
is given in the following listings, which include a Balance for
practically every purpose. In most cases, the Balance is offered
both in the conventional rider type and in the Chainomatic
type. Particular attention is directed to the Chainomatic
Balance, the use of which gives many days extra working time
in the course of a year.
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- The Chainomatic Balance has the usual
construction of Analytical Balances except that all weighings
from 1/10 mg. to 100 mg. are made by adding or decreasing weight
on the beam by means of a perfected chain. The length of chain
supported by the beam is increased or decreased, thereby changing
the weight carried by the beam, by rotating the crank at the
right side of the case.
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- This can be done while the beam is swinging
and the case closed, resulting in an enormous saving of time
when compared with the handling of small weights and riders and
the opening and closing of the glass door. Direct readings are
made from the graduated dial or column and vernier.
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- Dial-Reading Chainomatic
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- The Dial-Reading Chainomatic Balance
makes use of a revolving graduated dial to lengthen or shorten
the effective length of the chain. The chain is attached to the
revolving dial while the vernier remains stationary. The dial
is revolved by means of the crank at the right of the case. All
readings are made at eye level, reducing parallax to a minimum.
Graduated dial and vernier read from 1/10 mg. to 100 mg.
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- Column Chainomatic
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- The Column Chainomatic Balance makes
use of a graduated vertical column and vernier. The chain is
attached to a hook on the vernier. The vernier moves up and down
the graduated column when the crank is rotated. Graduated column
and vernier read from 1/10 mg. to 100 mg.
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- Movable Index or "Auto Dex"
- (Patented)
- In adjusting the equilibrium of an analytical
balance, it is customary to do so by means of the adjusting nut
at the end of the beam. This necessitates raising and lowering
the front sash several times and is liable to introduce an error
owing to the warmth of the hand when handling the beam. With
a Becker Balance equipped with a movable Index (Auto-Dex), controlled
by a thumb wheel at the left front of the balance case, a slight
turn of the thumb wheel moves the index plate to left or right
as necessary until the indicator is coincident with Zero. This
method saves time, eliminates the necessity of touching the adjusting
nut, and greatly increases the life of the agate edges.
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- Beam Arrest (Releasing Mechanism)
- The beam arrest arms and the beam being pivoted
about a common axis, the supporting points of the arrest arms
move through the same arc as the supporting points of the beam
so that contact between edge and bearing always remains the same,
thus reaching the acme of balance construction, the shifting
of the end bearings with the consequent dulling of the agate
edges being completely eliminated.
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- Advantages of Magnetic Damper
- Becker Analytical Balances, both Rider and
Chainomatic, can be supplied with built-in Magnetic Damper. The
particular advantages of the Magnetic Damper are:
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- 1. Brings indicator (pointer) to rest almost
immediately.
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- 2. Does not affect the sensitivity of the
balance.
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- 3. Unnecessary to calculate the rest point
by the swing method.
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- 4. Greater rapidity in weighing. Some operators
estimate a saving of approximately 50% in time.
- 5. The magnet can be lifted instantly from
the metal plate, permitting the balance to be used without any
damping action if so desired.
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- Equilibrium Adjuster for Column
Chainomatic Balances
- (Patented)
- This device makes use of the chain to obtain
equilibrium without using the adjusting nut at the end beam.
With the 0 of the vernier and the 0 of the graduated column coincident,
the vernier hook carrying the chain can be made to move up or
down by means thumbscrew on the top (outside) of the case, until
equilibrium is obtained. This can be done while the beam is swinging
and the case closed, resulting in a great of time and saving
the agate edges.
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- Equilibrium Adjuster for Dial
Reading Chainomatic Balances
- (Patented)
- The balance is brought to perfect equilibrium
quickly by means of the crank at the right of the case. The zero
of the vernier is then made coincident with the the dial. The
vernier movement is controlled by a small knob at the right of,
and near the top of the case. This is done quickly while the
beam is swinging and the case closed, resulting in a great saving
of time, and saving the agate knife edges.
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- Equilibrium Adjuster for Analytical
Rider Balances
- (Patented)
- This device, which is standard equipment
on all Becker Analytical Rider Balances, makes use of a chain
to obtain equilibrium without using the adjusting nut at the
end of the beam. The hook carrying the chain can be made to move
up or down by means of the thumb screw on the top (outside) of
the case, until equilibrium is obtained. This is done while the
beam is swinging and the case closed, resulting in a great saving
of time, and saving the agate edges.
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- © R. Paselk
- Last modified 22 July 2000
