AN IMPROVED PYROMETER OR INSTRUMENT FOR MEASURING HEAT
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Albert Sauvée at the Office of the
Commissioners of Patents on the 9th May 1882. A communication from
abroad by Emile Hilaire Amagat, of Lyons, in the Republic of France.
ALBERT SAUVÉE, Civil Engineer of 22 Parliament Street, Westminster in
the County of Middlesex "AN IMPROVED PYROMETER OR INSTRUMENT FOR
MEASURING HEAT" a communication fro:n abroad by Emile Hilaire Amagat, of
Lyons, in the Republic of France.
The object of this invention consists in an improved Pyrometer for measuring
the temperature of a body either gaseous, liquid or solid, where ordinary
thermometers cannot be employed, and is based on the principle that when a
rather thin metallic tube is kept in contact with a heated body, if a current of
water flows at the same time through this tube at a proper speed, the increase of
temperature of the water is limited to a few degrees, and of course this increase
varies with the temperature of the heated body.
I will proceed to describe the apparatus for carrying this into effect:
It consists of a metallic tube either in copper, brass, or other suitable metal,
which I prefer to make spiral. The two ends of the spiral are continued vertically,
and open into two separate small chambers. In each of these chambers is placed a
small thermometer and each chamber is connected with a pipe, one serving to
convey a current of water or other suitable liquid to the spiral tube and the other
to allow it to flow out. This is enclosed in a cylindrical case made of iron, fire
clay or any other suitable material and is provided with a longitudinal opening to
perimit of reading the indications on the scales of the thermometers. The cylinder
also contains two partitions provided with holes to allow the tubes to pass through
which serve to prevent the radiation of the heat up the case.
In order to find the temperature of any body the lower end of the apparatus is
either immersed or brought into close proximity to that body always taking care
to keep away the top which carries the thermometers. The current of water (flowing
at a fixed and known speed) enters the first chamber, the temperature being
indicated on the first thermometer. The water then flows through the spiral tube
and up into the second chamber where the second thermometer shews the increased
temperature of the water on leaving the body.

page_text: The degree of heat desired to be ascertained depends on the difference of the
two temperatures of the water as indicated by the two thermometers, and provided
that the speed and current of water be constant (which I regulate by any suitable
known means) then the difference of temperature on the two thermometers will
always be the same for the same degree of heat in the body to be measured.
From results first obtained by experiments with the apparatus I construct a
table or scale which will shew for every degree of heat acquired by the water in
passing through the apparatus the corresponding heat of the body. For instance
in order to ascertain an unknown temperature by this means, I take the difference
of the indications of the two thermometers and find on the table the temperature
corresponding to the difference and add to this the heat of the water on entering
the Pyrometer.
If preferable I construct a scale which can be set according to the speed of the
water, and so graduated that it will read at a glance the temperature of the body
desired to be found. This scale may be placed between the two thermometers or
in any other suitable position on the Pyrometer.
My improved Pyrometer can be applied to the measurement of heat of any body
either gaseous, liquid, or solid and I do not confine myself to the form nor materials
herein described, but modify the arrangement as best suited for the purpose.