White Bluffs spokesman. [volume] (White Bluffs, Wash.) 1907-1938, 1927-10-07
NEW COLORIMETER
AID TO INDUSTRY
Device Measures Color With
Extreme Precision.

Cambridge, Mass.-Human judg-
ment in the measurement of color has
been eliminated from industry by
new instrument developed at the Mas
sachusetts Institute of Technology,
called a colorimeter, used for auto
hatically measuring the color of any
substance rapidly and with extreme
precision.
In all previous instruments human
judgment has entered into the match
ing of an unknown color with stand
ard color, accuracy of such color
matching depending entirely upon the
skill of the observer and the quality
of light. 1t can only be made with
such instruments by persons whose
color vision has been carefully stand
ardized.
The new colorimeter developed at
Technology by Prof. Arthur G. Hardy
and Frederick w. Cunningham of the
department of physics, does not de-
pend upon any human Judgment, and
the accurate records of colors come
from the machine as fast as samples
can be fed to it. The Importance of
such an instrument lies in it's value
to industry, in nearly every branch of
which control of color of it's prod
ucts is necessary.
Accurate measurement of color Is
the first concern of manufacturers of
fabrics, particularly in the delicate
shades which often deceive the eye.
Color control is also of basic impor-
lance in making of inks, dyes, paper,
and many other commodities. In the
manufacture of CONNECTIONS, one COM
pany alone makes chocolates in Is diff
ferent colors, each of which must be
kept at standard shade.
Makes Record on Paper.
The new machine not only measures
color accurately, but makes record
on paper by which it is possible to
match that shade at any time.
A powerful optical system and cleo
trical devices are employed in regis
tering color by this machine. The speci-
men color placed in the holder is H.
Illuminated by special tungsten fla
ment lamp which gives an ilumina-
ton so times more intense than full
sunlight. Water filters are used to
prevent the light from setting fire to
the sample. In making the measure
ment, magnesium carbonate, the
yryh fncst 11Ncf0 to-,
the standard of comparison. Light is
alternately reflected from the speci-
men and the magnesium carbonate
and acts upon photo-electric cell in
which 1t sets up an alternating cur
rent.
This current is fed to a vacuum
tube amplifier which increases the
power ten quintillion (1O,OOO,OOOO OO,-
OOO,O0O) times and automatically keeps
the amount of light from the speci-
men and the magnesium carbonate
balanced. The color of the specimen
is analysed at each wave length of the
spectrum and the record is reproduced
automatically by pencil moving over
a revolving drum. The result is de-
scription of the color, by means of
which the Identical shade may be re-
produced as often as desired.
Colorimetry is science that is still
In its infancy, but good start has
been made toward establishing stand
ards for colors. With this new ma
chine much delay and tedious expert
mentation is eliminated. 1t will even
go to the point Of establishing Just
how many shades or variations of any
given color are possible, down to the
most delicate that are practically i'm
possible of differentiation by the hui
man eye.
Needed in Industries.
Color Standardization is something
that enters into hundreds of indus.
tries, and In them is of paramount
Importance.
Take, as an example, cottonseed oil.
Refined cottonseed oil produced in
this country during the last year was
valued at around S23,O00O0O, the mar
ket value of which is determined
largely by it's color. Very minute diff
ferences mean variation of hundreds
Of thousands and even up to the mil
lions of dollars in the market value.
Sometimes, because of disagreement
between buyer and seller of con.
signment, over the color. there will be
suit over the amount involved
In one case seven tank cars of cot.
tonseed oil which called for color
t7.6 per cent red proved to he ia per
cent red which made difference of
$4,000 in the value.
Colorimetry also enters into health
studies, such as the skin and blood
tests, eye protective glasses. etc.
In standardizing and testing colors
the United States bureau of stand
ards Is cooperating with the light
house service, the railways, the steam
ship companies, and agencies dealing
with highway traffic. And yet, the bu
reau people say, the problems which
have been solved and the things that
have been done are insignificant com
pared with the things that still await
solution. Years of study and research
will be required to develop the science
of colorimetry to a point where most
of the demands can be met.