DE2209583A1 - Thermistor - Google Patents

Description

Patent attorney
Dipl.-Phys. Leo Thul
Stuttgart

CS. Jones 1

International Standard Electric Corporation, Lew York

Thermistor

The invention "relates to a device with an electrical Resistance element and a bracket.

The electrical device according to the invention includes a holder and an electrical resistance element with two connections and for each connection a lead wire in the form of a wire loop on a Side is connected to the connector and each of which is anchored in the bracket and at a distance from the Connection point with the connection results in an external connection.

The invention will be explained in more detail with reference to the drawings.

FIG. 1 shows a side view of a high-temperature thermistor probe as an embodiment of the invention;

Figures 2 and 3 show in perspective view other embodiments of the invention and

Figure 4 shows an assembled bracket in an end view, suitable for the version according to Figure 1.

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According to Figure 1, the probe consists of a thermistor bead 2 made of zirconium oxide with up to 25 percent by weight Rare earth oxides with a negative temperature coefficient resistor with two short lead wires 3 and 4, preferably platinum.

The bead 2 is within an open chamber 1a at one end of a holder 1 made of sintered silicon dioxide arranged. Starting from this chamber 1a to the other end of the holder, there are four channels 7, 8, 9 and 10 provided. In a pair of channels 7 and 8 there is a lead wire 5 in the form of a wire loop from Ghromniekel wire arranged through the channel 7 leads to the chamber 1a, where the part 5a is connected to the platinum wire 3 by means of spot welding and which then continues runs back through the channel 8 and exits at the other end of the bracket.

The two free ends of the wire 5 are tightly twisted together and form the outer connection 5b. In exactly in the same way, a second lead wire 6 in the form of a wire loop is arranged in the two channels 9 and 10, which is connected to the other platinum wire 4 at 6a and whose free ends are twisted at 6b. So both wires are anchored in the bracket.

The space around the thermistor bead 2 in the chamber 1a is covered with a highly thermally conductive ceramic cement, preferably an alumina cement, filled in to have a good thermal To get conductivity between the bead 2 and the holder.

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C.S. Jones 1

The holder can instead also be made of ceramic Material "consist and, as shown in Figure 4, of an outer tube 27 and an inner cross-shaped Part 28 "exist.

According to FIG. 2, the holder 12 is plate-shaped and "has" the grooves 13 »14 on one side 15 and the corresponding grooves 16 and 17 on the opposite Page 18. Wires 5 and 6 are arranged in the grooves similar to those of Figure 1 and with the thermistor bead 2, which is arranged in the recess 19, connected. The recess 19 can, as mentioned above, with Be filled with cement.

According to Figure 3, the holder 20 is again a plate. The grooves 21 and 22, those for the wire 5 and the grooves and 24, which are intended for the wire 6, are now on one side. The thermistor bead 2 is in a recess 26 is arranged. The recess 26, the surface 25, the bead 2 and the wires 5 and 6 are with covered with a cement that holds the wires 5 and 6 and at the same time forms part of the holder.

As indicated in FIG. 1 with the dashed line, the probe can be provided with a metal sleeve 11, preferably made of stainless steel or some other high temperature resistant metal to be provided as to serve additional mechanical protection against lateral mechanical forces and / or against the corrosive atmosphere. The sleeve 11 is intended to be the chamber 1a and preferably entirely or partially include terminals 5b and 6b as shown. Such a sleeve, but now rectangular in shape,

209838/077 1

C.S.Jones 1 V -> -

can also be used in the embodiments according to FIGS.

The thermistor probe can be used as a flame sensor, either in or next to the flame is arranged and is connected to an apparatus that extinguishes and / or the presence of the flame registered and after a certain time delay of the order of several seconds the Indicates change in the flame condition and emits a corresponding output signal. Such thermistor probes are suitable for monitoring and measuring temperatures up to over 1,000 C. Above this Temperature, a material is required for the wires and the housing that can withstand these higher temperatures can.

In all versions, parts 1, 12 or 20 can contain aluminum oxide or silicon dioxide with admixtures of Contain aluminum oxide.

Plants ;

10 claims

2 sheets of drawings

1 List of Reference Numbers

209838/0771

Claims (9)

Claims Device with an electrical resistance element and a holder, characterized , because the connections (3> 4) of the 3 resistance elements each have a wire loop (5,6) are connected that the holder (1, 12, 20) the wire loops (5, 6) spatially separated holds and that parts of the wire loops (5b, 6b) are led out of the holder (1, 12, 20). 2.) Device according to claim 1, characterized in that the electrical resistance element consists of one Thermistor. 3.) Device according to claim 1 or 2, characterized in that the holder (1) has four channels (7 »8, 9, 10) and that in two channels the parts a wire loop (5, 6) are arranged. 4 ·) Device according to one or more of the claims 1 to 3 »characterized in that the holder (1) from an elongated, tubular outer part (27) and an elongated, cross-shaped inner part (28) consists. 5 ·) Device according to one or more of claims 1 to 3 »characterized in that in the holder (12) for each supply wire (5, 6) of the electrical Resistance element (2) a pair of parallel grooves (13, 14/16, 17) is provided, which extend from a first to a second position and that the pairs of grooves on opposite surfaces (15, 18) are arranged. 209 8 3 8/0771 ♦ / · O.F S. Jones 1 * 6.) Device according to one or more of claims 1 to 3, characterized in that the two pairs of grooves (21, 22 / 2.5, 24) in the holder (20) the same surface (25) are arranged. 7.) Device according to one or more of claims I to 6, characterized in that the holder (1, 12, 20) a chamber (1a) or recess (19, 26) having. 8.) Device according to one or more of claims 1 to 7, characterized in that in the recess (19, 2Γ,) or in the chamber (1a) the electrical resistance element (2) is arranged and that the chamber containing the resistance element with a thermally well conductive cement is lined. 9.) Device according to claim 8, characterized in that the thermally conductive cement contains aluminum oxide. 0.) Device according to one or more of claims 1 to 9, characterized in that the holder (1) is arranged in a protective sleeve (11) made of stainless steel. Hö / m - 21.2.1972 209838/0771 Le e rs θ i t e