Evening star., 1936-11-15

|
inventive genius. Some Of the most
superior commercial products are the
results Of their tireless research.
Their methods for conducting expert
ments are as varied as they are
| fascinating.
There are. for example. three pos
| sible ways Of testing, as employed by
| the bureau. First, in the laboratory,
where ingredients are ascertained,
weighed or measured. Second. in
actual service, and, third, in simu-
lated service. BY simulated service is
meant duplication Of natural con-
ditions or such conditions as the
article to be tested would encounter
in actual service For example, it is
required to test the wearing qualities,
the endurance and durability Of a
certain paint, let US say. That paint
Is applied to some surface, such as a
wall or roof. 1t is then subjected,
artificially, to the heat of the sun, to
freezing temperatures, to thaws and
artificial rains until, in a brief but
intensive period, it has lived .
| lifetime.
MOST ingenious of the methods for
testing is that known as "auto-
matte testing" BY this means a
laboratory worker may start his
experiment under the proper condi-
tions and go away and forget about
it while he works on something else.
For the product or merchandise will
go right on testing itself, registering,
in most accommodating fashion, its
own progress the while.
An interesting example Of how this
automatic procedure is conducted Is
| the method of testing duralumin-
an alloy containing aluminium and
copper, that is used very extensively
in the manufacture of enormous
dirigibles or aircraft, such as the Los
Angeles. Strips Of the metal are SUBJ
! jected to the elements-artificially
created elements-over a certain
period of time and under much
greater intensity than they would
ordinarily be subjected to in service.
In order to duplicate natural condi-
tions, so far as possible, the strip to be
tested is not permitted to rest upon
anything, and is kept in the air by
means Of air jets that play upward
upon it with such force as to hold
it suspended. The metal. thus sus-
| pended, is subjected to much more
violent vibration than it would ex-
! perience as part of some aircraft in
actual operation. 1t receives during
the course OF the experiment between
200 and 400 million vibrations-or an
equivalent to 40 years actual service!
Adding machines and elevators are
products which are also subjected to
automatic tests, registering with
minute accuracy the number of times
they fail to operate correctly or
efficiently.
One Of the most curious of the
tests made at the bureau is that hav-
ing to do with the durability Of the
paper that is to be used for United
States currency While this may not
receive long wear in the hands of one
individual. over the course of dollar
bills lifetime, or the lifetime of any
| bill, it is subject to much wear and
tear. Hence it is necessary to use
paper of a predetermined strength
and durability.
This is based upon the ability Of
the paper to Withstand the strain OF
being folded three of four thousand
times. This is considered a good
average for potential folding qualities.
A machine was devised at the bureau
automatically to fold and refold cur
rency paper until it showed signs Of
wear. The currency stock experi-
mented upon showed resistance to
wear up to five thousand foldings.
Which is probably all any one bill
would be called upon to endure, as it
is inevitably in more or less con-
| tinuous service.
In a search for on-cracking Stucco
unique method was devised by the
bureau for determining the qualities
quality. A stucco-test building was
constructed out of doors. its walls
/ divided into panels. Manufacturers
were invited to submit certified
samples of their products, accom-
panied by a statement Of composition.
This sample was applied to the panel
assigned by a representative Of the
concern. AS a result of these tests
the best qualities of each separate
product were listed and new product
made, embodying these best qualities
and eliminating the inferior ones, so
that very superior product was the
result of the tests
OF INTEREST to women is the
machine designed to test womens
full-fashioned silk hosiery under con-
ditions similar to those encountered
in actual service. The top of the
stocking is repeatedly distended while
under tension at the upper and lower
ends. The ability of the stocking
to recover its shape after loading and
the number of times it can be
stretched without giving way or other
wise failing, are tabulated for pur-
poses of comparison with other makes.
A defective stocking, we are told, will
withstand only a few cycles on the
horizontal arms of this machine.
Another curious and clever con-
traption invented at the bureau is
the walking machine" This was
devised to reproduce the strain on
shoes produced by ordinary walking.
in order to test the endurance of the
shoe upper, the leather, Innings, stitch
ings and heels. The machine is
operated by a conveyor belt driven
over a bed of rollers and this pro-
vides walking surface across which
the shoes, attached to the spokes of
revolving wheel, can travel.
1t is by these and numerous similar
tests and experiments that the Ma
tional Bureau of Standards ascertains
the value of certain advertised mer-
chandise or products. In addition to
these means, research is continuously
under way in the laboratories, the
libraries, the workrooms of the
bureau to the end that Uncle Sam
may make the most of the taxpayers
y,1onnv And III is the knoulodoo fhuS