A New or Improved Mercurial Pyrometer.
Year: 1895

page_text: Date of Application, 1st June, 1895-Accepted, 6th July, 1895
[Communicated from abroad by the Firm of SCHAFFER & BUDENBERG, of
Buckau, near Magdeburg, in the German Empire, Engineers.]
A New or Improved Mercurial Pyrometer.
I, WILLIAM EDWIN HEYS of 70 Market Street, Manchester in the County
of Lancaster, Patent Agent, 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 :-
This invention relates to a new or improved mercurial pyrometer the construction
of which is illustrated by the accompanying drawings, to which reference is herein-
after made and in which Figure 1 represents a sectional side elevation, and Figure 2
a vertical section taken at right angles to the view shewn by Figure 1.
The instrument consists of a main tube R which is to be exposed in use to the
temperature to be measured. This tube may be constructed of wrought iron, steel,
or other suitable material capable of resisting the effects of the heat and pressure to
which it will be subjected. At the upper end of the tube there is fixed a pressure
gauge P, which may be of any suitable construction. The gauge illustrated is of the
steel tube type which is the preferred form. The lower part of the tube R, a
portion of which is represented as being broken away in the drawings to avoid an
unnecessary length in the figures, is of comparatively wide bore, and communicates,
through a narrow passage or bore, with the interior of the gauge tube M. By this
arrangement any pressure existing in the tube R will be indicated by the pressure
gauge in the usual manner.
In fitting the instrument for use, the wide bore part of the tube R, as well as a
part of the narrow bore, is filled with mercury. The remaining space in the tubes R
and M is filled with an inert gaseous fluid, such as carbon dioxide or nitrogen
preferably under pressure. For the purpose of supplying the gas under pressure,
the upper part K of the tube M may be provided with an inlet closable by a
screwed plug, as shewn. The object of filling up the tubes with the gas under
pressure is to prevent the boiling of the mercury at high temperatures.
When the tube R is exposed to beat, expansion of the mercury takes place, which
further compresses the gaseous fluid and imparts a corresponding motion to the
index finger or pointer. The dial of the gauge is graduated to indicate degrees of
heat corresponding with the pressures arising within the tube R under the action
of heat.
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 :-
1. A mercurial pyrometer constructed and arranged substantially as hereinbefore.
described and in which the expansion of the mercury under the action of heat
compresses a gas, the amount of the compression of the gas being indicated by a.
pressure gauge.
2. A mercurial pyrometer, constructed arranged and operating substantially-as-
herein before described and as illustrated by the accompanying drawings.
Dated this 31st day of May A D 1805
WILLIAM E. HEYS.