Improved Apparatus for Determining Temperatures at a Distance.
Year: 1885

page_text: PICATION.
Improved Apparatus for Determining Temperatures at a
Distance.
I, JAMES GRIEVE LORRAIN, of 3 Vernon Chambers, Southampton Row, in the
County of Middlesex, Consulting Engineer, do hereby declare the nature of my
Invention for IMPROVED APPARATUS FOR DETERMINING TEMPERATURES AT A
DISTANCE to be as follows:-
My invention relates to improvements in Electric thermotelemetry and has for
its object the indication of temperatures at a distance. Several forms of thermo-
telemeter have been devised but so far as I am aware none of them have come into
general use. This I believe to be because they have all required some mechanism
or combination of mechanical parts to transmit the indications or the elèctric
current corresponding with the temperatures to be indicated, and mechanism is
always liable to derangement in proportion to its complexity.
In the apparatus which is the subject of my invention no transmitting mechanism
(strictly speaking) is used or required.
•
In carrying my invention into effect I employ two or more strips or other shaped
pieces of different metals alloys or other suitable substances extending from the
transmitting station, or place whose temperature it is desired to know, to the.
receiving station, or place where it is desired that the temperature of the trans-
mitting station should be made known or indicated. At each end, that is at the
transmitting and receiving stations, the strips may be bound or soldered together
or otherwise placed in intimate contact with one another. Between the trans-
mitting and receiving stations they may be separated or otherwise insulated one
from the other. A complete conducting circuit is thus formed.
At the receiving station an indicating apparatus is placed. This consists of a
galvanometer, electrometer or other equivalent apparatus, and is placed in the
circuit above mentioned or in electrical connection therewith. Beside it a ther-
mometer may be placed so that the readings of the thermometer and of the
indicating apparatus may be compared. Any suitable form of thermometer may
be employed for this purpose. A table or chart showing with what temperatures
at the transmitting station the readings of the indicating apparatus correspond for
different readings of the thermometer may be used. This table or chart may be
printed, engraved or otherwise marked upon a card,.plate or other suitable surface.

page_text: The action of my apparatus is as follows:-If the temperature of one of the
junctions of the strips is higher than the other an electric current will pass through
the circuit. The greater the difference between the temperatures of the two
junctions the greater will be the energy of the current and consequently the
greater the deflection or the higher the reading of the indicating apparatus. This
reading will not represent the temperature at the transmitting station but the
difference between the temperatures of the two junctions; therefore in order to
determine the temperature at the transmitting station a thermometer must be
placed at the place where the other junction is. The temperature of this latter
being ascertained, the temperature at the transmitting station can be determined
by reference to the table or chart which shows what temperature at the transmitting
station a given reading of the indicating apparatus corresponds with at the
temperature shown by the thermometer.
I have stated above that the one junction may be at the transmitting station
and the other junction at the receiving station. It is not necessary however that
one of the junctions should be at the receiving station. The two junctions and the
indicating apparatus may be at three distinct places. The thermometer must of
course be beside one of the junctions namely the one which is not at the transmitting
station.
Instead of having two junctions I may join the strips at one extremity only and
I may connect the other extremities directly, or by conductors or wires, to the
indicating apparatus.
A number of indicating apparatus may conveniently be arranged in a frame
consisting of a structure having windows, holes or other equivalent spaces or points
each of which may present indications from a separate transmitting station, and
the said frame or structure may contain or bear the thermometer or thermometers
with which the indicating apparatus are compared, and also the table or chart or
tables or charts above referred to.
The strips may be of any convenient size or shape, as cylinders, plates &c. They
need not necessarily be of different metals, alloys or substances, as they will
produce effects if of different molecular structure or under the influence of widely
differing mechanical or physical stress.
Where a number of strips are employed I may cover one junction or set of
junctions by a shield of non-conducting material.
When the transmitting station is inside a building or structure or mass of
material I may place the other junction, where such is employed, outside, so as to
be in the external air or in water or in the ground.
In Factories, houses, works, &c. I may have one junction or set of junctions at
the transmitting station and one at a cellar, store, chimney or mass of material as
widely differing in temperature as possible from that of the transmitting station.
Where possible, I prefer to place the junction which is not at the transmitting
station where the temperature is either known or constant.
Dated this 18th laws of Anril 100%

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Determining Temperatures at a
Distance.
I, JAMES GRIEVE LORRAIN, of 3 Vernon Chambers, Southampton Row, in the
County of Middlesex, Consulting Engineer, do hereby declare the nature of my
invention for IMPROVED APPARATUS FOR DETERMINING TEMPERATURES AT A
DISTANCE and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
1
My invention relates to improvements in electric thermo-telemetry and has for
its object the indication of temperature at a distance. Several forms of thermo-
telemeter or apparatus for indicating temperatures at a distance have been devised,
but so far as I am aware none of them have come into general use. This I believe
to be because they have all required some mechanism or combination of mechanical
parts to transmit the indications or the electric current corresponding with the
temperature to be indicated, and mechanism is always liable to derangement in
proportion to its complexity. In the apparatus which is the subject of my inven-
tion no transmitting mechanism (properly so called) is used or required.
In carrying my invention into effect I employ two or more strips, wires, or other
shaped pieces of different metals, alloys, or other suitable substances extending
from the transmitting station or place whose temperature it is desired to know to
the receiving station or place where it is desired that the temperature of the
transmitting station should be made known or indicated. At each end, that is at
the transmitting and receiving stations (subject to exception hereinafter mentioned)
I bind or solder the strips together or otherwise place them in intimate contact
with one another.
Between the transmitting and the receiving stations, that is throughout the
length of the two strips which extend between the stations, I generally separate
and
ог
otherwise insulate the strips one from the other. A complete conducting
circuit is thus formed. I sometimes instead of extending or continuing the strips
throughout the whole distance from one station to the other employ ordinary line
wire to connect the two, but I do not recommend this as intermediate junctions
introduce sources of error. At the receiving station an indicating apparatus is
placed. This consists of a galvanometer electrometer or other equivalent apparatus
and is placed in the circuit above mentioned or in electrical connection therewith.
Instead of joining the two strips together at the receiving end and thus forming
a junction their free ends may be each connected to one terminal screw of the
indicating apparatus. But prefer to make the two junctions as above described
and then to cut one of the strips at some convenient place close to the junction
at the receiving station and insert the indicating apparatus in the place thus cut.
With some forms of indicating apparatus I connect it as a shunt to the main
circuit and sometimes insert a resistance in the main circuit between the points of
derivation of the shunt..
At, or in close proximity to the receiving junction a thermometer or temperature
measuring apparatus is placed so that the readings of the thermometer and of the

page_text: indicating apparatus may be compared. In some instances I form a cup or
depression in the metal of the junction which is then filled with mercury into
which the bulb of the thermometer dips. Any suitable form of thermometer may
be employed for this purpose. I also employ a table or chart showing with what
temperatures at the transmitting station the readings of the indicating apparatus
correspond for different readings of the thermometer. This table or chart is
printed, engraved or otherwise marked upon a card plate or other suitable surface.
One form of chart consists of a card upon which the thermometric scale is marked
off on the ordinates and the scale of galvanometric deflections on the abscissae or
vice versa in such manner that the curves traced will readily show the temperatures
which are required to be known. Or I use a table in which the temperatures (as
shown by the thermometer) are set off in one row of figures and the deflections in
another row at right angles to the first, and at the points or spaces at which
imaginary or real lines drawn at right angles from such figures would meet I place
or inscribe figures which represent the temperatures which are required to be
known and which correspond with the deflection shown on the galvanometer and
the temperature as shown on the thermometer. Other forms of chart or table will
suggest themselves and I desire it to be understood that I do not limit myself to
any particular form of chart or table.
The action of my apparatus as follows:-
When the temperature of one of the junctions of the strips is higher than the
other an electric current will pass through the circuit. The greater the difference
between the temperatures of the two junctions the greater will be the energy of
the current and consequently the greater the deflection or the higher the reading
of the indicating apparatus. This reading will not represent the temperature at
the transmitting station but the difference between the temperatures of the two
junctions, therefore in order to determine the temperature at the transmitting
station a thermometer must be placed at the place where the other junction is.
The temperature of this latter being ascertained the temperature at the trans-
mitting station can be determined by reference to the table or chart which shows
what temperature at the transmitting station a given reading of the indicating
apparatus corresponds with at the temperature shown by the thermometer.
I have stated above that the one junction may be at the transmitting station
and the other junction at the receiving station. It is not necessary however that
one of the junctions should be at the receiving station. The two junctions and
the indicating apparatus may be at three distinct places. The thermometer must
of course be beside one of the junctions, namely the one which is not at the
transmitting station.
When I employed a number of indicating apparatus to show at one place the
temperatures of several other places it is convenient to arrange them in a frame
consisting of a structure having windows, holes, or other equivalent spaces or points
each of which may present indications from a separate transmitting station, and
the said frame or structure may contain or bear the thermometer or thermometers
with which the indicating apparatus are compared and also the table or chart. or
tables or charts above referred to. I do not however always use a separate
indicating apparatus for each line coming from a different transmitting station, but
sometimes employ a single indicating apparatus which I-switch into connection
with the different lines as required.
The strips may be of any convenient size or shape as cylinders, plates, wires and
the like. They need not necessarily be of different metals, alloys, or substances as
they will produce effects if of different molecular structure or under the influence
of widely differing mechanical or physical stress. I do not limit myself to the use
of one pair of strips or one pair of junctions as I sometimes increase the number
of parts to gain increased effect.
When the transmitting station is inside a building, or structure, or mass of
material I sometimes place the other junction, where such is employed, outside
so as to be in the external air or in water or in the ground. In this last case

page_text: I prefer to have it sufficiently deeply buried to be in earth or rock of constant
temperature.
In factories, houses, works and the like I may have one junction or set of junc-
tions at the transmitting station and one at a cellar store, chimney, or mass of
material as widely differing in temperature as possible from that of the transmitting
station.
I sometimes prefer to place the junction which is not at the transmitting station
in a place where the temperature is either known or constant. Where this is the
case the thermometer may be omitted. One method of keeping the receiving
junction at a constant temperature is by inserting it in a chamber the temperature
of which is controlled or regulated as described in the Specification accompanying
my Letters Patent No. 339 of the year 1885.
It is sometimes necessary to know the temperature of one place at several other
places and this can be done by taking branches from one common junction, or set
of junctions, placed at the transmitting station & running them to separate
receiving stations or indicating 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 :-
1. The improved apparatus for determining temperatures at a distance substan-
tially as specified.
2. In apparatus for determining temperatures at a distance the combination of
an indicating apparatus a thermometer and a table or chart substantially as and
for the purpose specified.
3. In apparatus for determining temperatures at a distance the combination of
an indicating apparatus, a table or chart, and a constant temperature chamber
substantially as specified.