Year: 1887

page_text: Date of Application, 24th Sept., 1887
Complete Left, 23rd May, 1888
Complete Accepted, 29th June, 1888
We, ANATOL SIEGERT and WALTER DÜRR Engineers of Munich in the Empire of
Germany, do hereby declare the nature of this invention to be as follows:—
In devices heretofore used for measuring the density of gases, corrections have to
be made for temperature and pressure; this invention consists in such improvements
as shall render such corrections unnecessary, thus enabling the device to show the
density without being disturbed by temperature or pressure.
A convenient device for measuring density has heretofore been made, by mounting
a hollow and air tight globe on one arm of a balance, the other arm thereof
bearing a counterbalance. The density of the gas in which this apparatus is
placed is indicated by the rising or falling of the globe, the latter carrying a finger
moving over a suitable scale, allowances or corrections having afterwards to be made
for the disturbing influences of temperature and pressure.
The improvements consists in providing the counterpoise arm of the balance beam
with an automatically shifting weight said weight being moved by the increase or
decrease of pressure or temperature along the beam so as to compensate the equivalent
movement of the aforesaid globe caused by or due to such increase or decrease of
pressure or temperature.
For this purpose, upon the said arm of the beam is fixed a tube of U or other
convenient form, the said tube has one closed and one open end, the closed end being
nearer to the pivot of the beam. Such tube is partly filled with liquid such as
quicksilver sulphuric acid or the like, so that a certain quantity of air or gas is enclosed
in the closed branch of the tube. The whole device is introduced into an air tight
case, into which the gas to be tested may be introduced. The pressure or temperature
of this gas is communicated to the air enclosed in the U tube and the latter is
correspondingly expanded or contracted thus moving the liquid in the tube more into one
or other branch thereof thus shifting the centre of gravity thereof away from or
towards the pivot of the beam for an amount calculated to exactly counteract the
effect of the pressure or temperature on the globe. Thus enabling the density of
the gas to be truly shown on the scale.
Dated this 24th day of September 1887.
HERBERT & Co.,
Agents to Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Devices for Measuring the Density of Gases.
We ANATOL SIEGERT and WALTER DÜRR, Engineers of Munich in the Empire
of Germany do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
In devices heretofore used for measuring the density of gases corrections have
to be made for temperature and pressure this invention consists in such improvements
as shall render such corrections unnecessary thus enabling the device to show the
density without being disturbed by temperature or pressure.
A convenient device for measuring density has heretofore been made by mounting
a hollow and air tight globe on one arm of a balance, the other arm thereof bearing
a counterpoise. The density of the gas in which this apparatus is placed is indicated
by the rising or falling of the globe the latter carrying a finger moving over a suitable
scale allowances or corrections having afterwards to be made for the disturbing
influences of temperature and pressure.
The improvements consist in providing the counterpoise arm of the balance beam
with an automatically shifting weight said weight being moved along the beam by
the increase or decrease of pressure or temperature so as to compensate the equivalent
movement of the aforesaid globe caused by or due to such increase or decrease of
pressure or temperature.
For this purpose upon the said arm of the beam is fixed a tube of U or other
convenient form, the said tube has one closed and one open end the closed end being
nearer to the pivot of the beam. Such tube is partly filled with liquid such as
quicksilver, sulphuric acid or the like so that a certain quantity of air or gas is enclosed
in the closed branch of the tube. The whole device is introduced into an airtight case
into which the gas to be tested may be introduced. The pressure or temperature of
this gas is communicated to the air enclosed in the U tube and the latter is
correspondingly expanded or contracted thus moving the liquid in the tube more into
the one or other branch thereof thus shifting the centre of gravity thereof away from
or towards the pivot of the beam for an amount calculated to exactly counteract the
effect of the pressure or temperature on the globe, thus enabling the density of the gas
to be truly shown on the scale.
Referring to the accompanying drawing:
A represents the closed receptacle and a b c d the U tubel'aforesaid closed at a and
open at d:

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what we
claim is
In combination with a densometer as a counterweight thereto a U tube a b c d or
equivalent closed at one end and partly filled with suitable liquid.
Dated this zord day of May 1888.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C.
Agents to Applicants.