A NEW OR IMPROVED PYROMETER
Year: 1884

page_text: 27
I JAMES BLATCH Cox of Torquay in the County of Devon, House Agent de
hereby declare the nature of said invention for "A NEW OR IMPROVED PYROMETER
to be as follows:-
This pyrometer consists of a pipe of small internal capacity closed at one end
and at the other end communicating with the closed upper end of one shank of a
metallic glass or other tube bent down into a long U shape, the other shank of
such tube being open to the atmosphere. The first named shank of the tube is
closed by a stopper. When this stopper is in the first instance removed, quicksilver
is poured in through the other open shank so as to partly fill the tube, the air
escaping freely at the top of the other shank. The stopper is then closed airtight.
To use the apparatus the aforesaid pipe is inserted into the oven or furnace, the
heat of which is to be tested and indicated. The heat in the oven or furnace will
heat and expand the air contained in the pipe and the tension of the air accordingly
depresses the quicksilver in one shank of the bent tube and thereby raises it in the
other shank and the rise and the corresponding temperature is indicated by divisions
marked on the tube or on a gauge plate attached thereto. If the tube is entirely
made of metal I employ an indicating float resting in or on the quicksilver. The
pyrometer pipe may be of iron or other suitable metal or if employed for high
temperature be made of or covered with fire clay or other fire resisting material.
Where this pipe is required to be of considerable length the bore is correspondingly
reduced.

page_text: "
I, JAMES BLATCH Cox of Torquay in the County of Devon House Agent do
hereby declare the nature of said Invention for "A NEW OR IMPROVED PYROMETER
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This pyrometer consists of a pipe of small internal capacity closed at one end
and at the other end communicating with the closed upper end of one shank of a
metallic, glass, or other mercury tube bent down into a long U shape, the other
shank of such tube being open to the atmosphere. The first named shank of the
tube is closed by a stopper."
In the accompanying drawings I have shown two forms in which this pyrometer
may be made. All the views are sectional elevations.
In Figure 1 A is the tube intended for insertion in an oven or furnace for
ascertaining the heat therein and having one end sealed or closed, the other
communicating with a bent tube B containing mercury or other suitable liquid;
this tube may conveniently be made of glass. C is a screw stopper for releasing
the air so as to allow the mercury to find its level when poured in at the other
open slank of the tube B. D is an index plate. Or the index divisions may be
on the tube B itself. If the tube B is made of non-transparent material such as a
metal I employ an indicating float resting in or on the quicksilver and projecting
above the top of the tube B.
In Figure 2 the bent tube is dispensed with and a wider straight tube
substituted. C is the screw stopper for releasing the air as in Figure 1 and D the
index plate.
When the stopper C is in the first instance removed quicksilver is poured in
through the open end B of the tube B so as to partly fill the tube B the air
escaping freely at the hole for the stopper C. The stopper C is then closed airtight.
To use the apparatus the aforesaid pipe A is inserted into the oven or furnace the
heat of which is to be tested and indicated. The heat in the oven or furnace will
heat and expand the air contained in the pipe A and the tension of the air
accordingly depresses the quicksilver in one shank of the bent tube B. Figure 1
and thereby raises it in the other shank or as regards Figure 2 the quicksilver
rises in the tube B and the rise and the corresponding temperature is indicated by
divisions marked on the tube or on the gauge plate D attached thereto. If the
tubes A B are entirely made of metal I employ an indicating float resting in or on
the quicksilver and projecting above the top of the tube B. The pyrometer pipe A
may be of iron or other suitable metal or may if employed for high temperatures
be made of or covered with fire clay or other fire resisting material. Where this
pipe is required to be of considerable length the bore may be correspondingly
reduced.
The pipe A containing only a small quantity of air the exact amount of which
can be easily ascertained, the heat indicated by its expansion can be easily graduated
on the index scale and involves the use of a comparatively short mercury tube
which however by preference is of a comparatively large diameter as shown.
±

page_text: 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
The new or improved air pyrometer consisting mainly of a pipe A containing
air, and provided with air outlet stopper C, and the mercury containing tube B
with graduated index all substantially as shown and described.
BREWER & JENSEN,
For the Applicant.