Improvements in Apparatus for Measuring and Indicating the Pressure of Gases.
Year: 1898

page_text: Date of Application, 17th Oct., 1898
Complete Specification Left, 17th June, 1899-Accepted, 5th Aug.,
1899
Improvements in Apparatus for Measuring and Indicating the
Pressure of Gases.
I, MAX ARNDT, of Monheimsalle, Aachen, Germany, Engineer, do hereby
declare the nature of this invention to be as follows:
The apparatus of this invention has for object to measure and indicate slight
differences in the pressure of gases as compared with atmospheric air, and com-
prises a balance provided with a pair of vessels, one at each end of the balance
beam, in communication with each other through a tube and supplied with a
liquid. One of the vessels is open to the atmosphere and the other placed in
Any difference of
communication with the gas to be measured or weighed.
pressure in the two vessels causes a variation in the level of the liquid and a
This movement is
displacement of the vessels attached to the balance beam.
transferred to a pointer which is thereby moved over an indicating scale. Before
commencing an operation the pointer is adjusted to its initial or zero position by
means of weights adjustable on the balance beam and pointer. Also for shewing
the difference of level of the liquid an indicating scale may be attached to or
placed adjacent to each vessel.
The apparatus may be connected in a known way with electric signalling and
recording apparatus.
CAPITAINE & VON HERTLING,
15, Tooks Court, London, E.C., Agents for the Applicant.
Improvements in Apparatus for Measuring and Indicating the
Pressure of Gases.
I, MAX ARNDT, of Monheimsallee, Aachen, Germany, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
-
The apparatus of this invention has for object to measure and indicate slight
differences in the pressure or tension of gases as compared with, or relatively to,
atmospheric air.
The accompanying drawing shews the apparatus of the invention in side view.
The apparatus comprises a balance a of any suitable construction the indicating
pointer of which moves on a knife edge b; two vessels d¹, d, one at each end of
the balance beam, in communication with each other, for example, through a

page_text: tube e which in any case is fixed relatively to the two vessels which are supplied
with a liquid serving to imprison the gas and indicate the level of the same;
and an indicating scale over which the pointer of the balance can move.
One, d, of the vessels is placed in communication with the reservoir or space
containing the gas the pressure of which is to be measured and indicated. This
communication may, for example, be established by a flexible tube adapted to
follow all the oscillations of the balance. The drawing shews such a tube g
attached to the vessel at a projecting tube part f and led to the line of the axis
of rotation (knife edge) of the balance. From this point the connection with the
gas reservoir may be made in any way.
The other, d, of the two vessels is open to the atmosphere, say at i.
The weights internally screw threaded and each adjustable on a screw rod
projecting from the pointer serve for the adjustment of this latter to its initial
or zero position on the scale 1, this being the position when the two columns of
liquid, water for instance, k are at the same level in the two vessels. When a
change of pressure takes place in the gas reservoir and consequently also in the
gas vessel d the liquid will rise or fall therein while an opposite movement
of the liquid will take place in the vessel until the difference in the height of
the two columns is in equilibrium with the pressure or tension of the gas.
By reason of the variation in the height of the liquid columns the centre of
gravity of the apparatus varies correspondingly and according to the pressure
of the gas at any moment.
For shewing the level of the liquid columns, indicating scales m, n, may be
attached to or placed adjacent to the respective vessels each one indicating by
its divisions whether the liquid stands at the same level as that indicated by the
position of the pointer on the scale 7.
The apparatus may be used for many purposes, for instance, as a measurer of
the draught of steam generator and other furnaces, or as a manometer in the
conduits of illuminating gas, also in carrying out pyrometric experiments and
for shewing the rarefaction of the air in gas absorbing apparatus.
The apparatus may be connected in a known way with any suitable electric
signalling and recording apparatus.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
An apparatus for measuring and indicating the pressure of gases consisting of
two vessels d', d, supplied with a liquid up to a certain height, one of said vessels
being open to the atmosphere and the other in communication by a tube with
the reservoir or space containing the gas of which the pressure is to be measured,
the two vessels being in communication with each other through a tube e, in one
piece with or in rigid connection with the two vessels which are rigidly attached
to a balance whose knife edge is located between the two vessels as near as possible
to the centre of gravity of the apparatus in the state of rest position, in the
manner that both vessels may move around the turning axis of the balance with-
out changing their relative positions when variations take place in the
level of the liquid in the vessels which variations and also the state of rest position
are indicated on scales 1, m, n, substantially as described and shewn.
Dated this 17th day of June 1899
CAPITAINE & VON HERTLING,
15, Tooks Court, London, E.C., Agents for the Applicant.