DE3018013A1 - Thermal sensor for laboratory or measuring use - is composite metal strip embedded in heat resistant plastics - Google Patents

Abstract

A thermal sensing element is produced in strip format ready for use without the need for soldering or welding. The unit has a carrier foil (1), produced from a glass fibre reinforced plastics that is heat resistant. A thin adhesive layer (2) is located on either side and bonds with heat sensitive layers (3) of alloyed metals e.g. NiCr or CuNi. The composite strip is embedded in an extruded bent resistant plastic (6), e.g. polyamide. Perforations (4) are formed in alternate series that are staggered along the length of the strip. The composite sensing strip is joined by welding, soldering, or forming (5) along the one edge. The edge of the tape is secured using the perforations.

Description

4 - Hanau, May 9, 1980 ZPL-Zw / Bö

W. C. Heraeus GmbH, Hanau Patent and utility model auxiliary application

"Ribbon-shaped thermocouple"

The invention primarily relates to a ribbon-shaped thermocouple For use in laboratory and test fields as a thermal sensor.

There are ribbon-shaped thermocouples known for the same purpose. With these thermocouples the user must! ¹ Either order a finished thermocouple from a manufacturer or manufacture a thermocouple yourself from prefabricated thermal cables.

The object of the invention is to create a thermal line from which in the simplest possible way without welding or soldering an operational thermocouple can be produced, adapted to the particular application.

This object is achieved by the features listed in claim 1.

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Further refinements of the invention can be found in the description and drawing of exemplary embodiments.

Show it:

FIG. 1a shows a thermocouple according to the invention in an encapsulated design, in which the two thermoconductors are one above the other lie and have a carrier film between them (preliminary product);

FIG. 1b shows a modified form similar to FIG. 1a;

Figure 2 shows another embodiment of the thermocouple according to the invention, wherein the two thermocouple legs are arranged next to one another and between carrier films;

Figures 3a, 3b and 3c

different connections on the finished thermocouple.

As shown in Figure 1, are on a carrier film 1 made of high temperature-resistant plastic, such as polyimide or fiberglass-reinforced synthetic resin, each with a thin (polyimide) adhesive layer 2 applied and on this in turn the thermal legs 3 made of different metals or metal alloys, such as NiCr / CuNi, which on a Side protrude over the carrier film. The protruding areas (tracks) of the thermocouple legs 3 are through Roll welding seam 5 (spot welding, rolling, pressing, soldering, etc.) permanently and permanently connected to one another. The connecting surfaces 5 lie one above the other in the middle at one edge the band height.

The otreifenverbund can be perforated in certain places be, as shown, along two lines, preferably

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with long holes. One perforation 4 "is located in the proximity of the interconnected areas of the thermo legs, also called thermal node 5; the second perforation will be a short distance from and parallel to the first arranged.

The composite strip is of a sheath 6, for example made of an extrudable or injectable plastic, which is sufficient temperature resistant, e.g. polyimide or PFA. Preferred is one that is transparent on at least one side or at least a translucent shell.

To manufacture a thermocouple, cut a _{% of the} desired length of the cable (tape). Then an edge strip of the cable (tape) is cut off at the outer perforation facing the thermal node 5, except for a remainder of about 10 mm at the lower end. This end forms the measuring point 7. The perforation 4 furthest away from the measuring point serves to maintain the * outer covering layer, so that the

Plastic wrapping is prevented.

* Connection with the

Instead of a double parallel perforation, an arrangement according to Figure 1b can also be selected. There is a rack-like formation of the strip composite shown. In addition, a marking 11 can be provided which shows how far the tooth gaps have been cut out should be to leave measuring points.

In the embodiment according to FIG. 2, the two interconnected thermal legs 3 are next to one another on a carrier film 1 laminated by means of an adhesive layer 2. This bond is to the left and right of the planar connection

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2,

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of the webs 5 perforated at 4 so that a median strip. arises along the longitudinal center axis, which can later be removed is. This arrangement is covered by a non-adhesive tape 8 (plastic film) and by a adhesive polyiraid tape 9 protected (composite cover).

The thermal legs 3 can overlap or Have interlocking areas 5. The connection of the areas 5 of the thermocouple legs 3 takes place in same process as in FIG. 1. Hot rolling is preferred.

To produce a thermocouple, a desired length of the tape is cut off and the perforated central strip (between the parallel perforations 4-4) except for a remainder of about 10 mm (measuring point) by tearing open removed from the perforation. Excess parts are disposable.

The entire design of the thermocouple is made in such a way that that an inexpensive production in the form of yard goods is possible. The finished tape has a total thickness of about 0.1 mm up to 1 mm, the carrier film having a thickness in the range from 50 / ui to 100 / um, and the carrier legs 3 a Have a thickness of about 50 mm to 200 µm. The cover sheet or the sheath also has a thickness of about 0.1 mm to 0.5 mm. Although in the embodiment of Figure 1 Production of the casing by extruding or injection molding the plastic was preferred, other types of casing can also be selected.

In all embodiments of the invention there are connection contacts provided, as shown e.g. in Figures 3a and 3b,

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which are used for soldering wires or the like. the Connection points or areas can be selected by the user.

FIG. 3a shows an embodiment of the connection contacts for the thermocouple shown in FIG. 1, with connection areas are exposed, and at 10 a plastic screw 12 penetrates the composite strip and presses the two connecting wires on the thermo legs 3 (Figure 3b).

In FIG. 3c, in the embodiment of the thermocouple according to FIG. 2, it is shown how the connecting wires are connected to exposed connection areas of the thermocouple legs 3.

Conventional solders, preferably a tin solder, are applied to the connection points.

The particular advantage of the invention is that the user can easily produce the optimal shape and size for the respective application and the respective attachment of the thermocouple without soldering or welding the thermocouple legs. Furthermore, embodiments of the invention are described which, despite inexpensive starting materials, withstand the temperatures in question over the long term. The main application is for temperature measurements between about -80 ⁰ C and +. 200 C

The invention is not limited to the embodiments shown and described. Modifications can be made without going beyond the scope of the invention leaving.

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The invention also includes all combinations and sub-combinations the claimed, described and illustrated features, both in combination with one another as well as in combination with features known per se.

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Claims (12)

Hanau, May 9, 1980 ZPL-Zw / Bö WC. Heraeus GmbH, Hanau Patent and utility model auxiliary registration "Ribbon-shaped thermocouple" Claims y. Ribbon-shaped, thin thermocouple, characterized by a) two strip-shaped, metallic thermocouple legs (3), which are inextricably connected to one another in flat areas (tracks 5), b) a carrier film (1) made of plastic, which at least on one side is provided with an adhesive layer (2), c) a connection of the adhesive layer with the thermal legs (3) such that d) the desired length of tape can be separated and partial areas of the composite can be detached in such a way that in an edge area, in which the thermo legs (3) are firmly connected, a measuring point (7) remains, in other areas the However, electrically isolate the thermo legs (3) from one another - 2 - < 130046/0488 and electrical connections are attachable to the thermal legs. 2. Thermocouple according to claim 1, characterized in that the adhesive layer (2) is applied to both sides of the carrier film (1). 3. Thermocouple according to claim 2, characterized in that the thermal legs (3) on both sides of a carrier film O) sandwiched one above the other and by means of the Adhesive layers (2) are connected to the film (1). 4. Thermocouple according to one of the preceding claims, characterized in that the composite body of a Plastic sleeve (6) is surrounded. 5. Thermocouple according to claim 1, characterized in that the thermal legs (3) arranged next to each otherfc.over the adhesive layer (2) with the carrier film (1) made of plastic are connected. 6. Thermocouple according to claim 5, characterized in that a non-adhesive plastic film (8) is arranged on the side of the thermal legs (3) facing away from the adhesive layer (2) is. 7. Thermocouple according to Claims 5 and 6, characterized in that that the thermal legs (3) and the non-adhesive plastic film (8) in turn with the Adhesive layer (2) connected cover (9) are arranged. 8. Thermocouple according to one of the preceding claims, 13004 6/0488 characterized in that the thermal legs (3) at in The longitudinal direction of the tape running tracks (5) are firmly connected, the tape cut transversely to the longitudinal axis and parts of the shell and composite are removed so that a measuring point (7) remains in an edge area. 9. Thermocouple according to claim 8, characterized by at least one perforation (4) for releasing parts of the network. 10. Thermocouple according to claim 9, characterized in that the perforation (4) is designed to penetrate the sandwich-like composite and part of an edge strip (at 5) are separated out transversely to the perforation. 11. Thermocouple according to claim 9, characterized in that the perforation (4) on one side, the carrier film (1), the Adhesive layer, (2), the thermal leg (3) and the non-adhesive plastic film (8) penetrates and by tearing it open a tab-like strip from one end in the middle between two perforations (4) parts of the Composite can be triggered, so that a measuring point (7) remains in another end area (of the band section). 12. Thermocouple according to claim 1, characterized by free selectable places (areas) for electrical connections. 130046/0488