DE8317879U1 - QUICK-SPEED ELECTRIC THERMOMETER - Google Patents

Description

83 170 ET

PAT / Dr.Br-Ca 05/26/1983

Degussa Aktiengesellschaft

Weissfrauenstrasse 9 6000 Frankfurt am Main 1 10

Fast acting electrical thermometer 15

The innovation concerns a fast-responding electrical thermometer, consisting of a sheet resistor with leads that are inside a sleeve made of a material that conducts heat well by means of a potting compound is fastened flat on the bottom of the sleeve, which in turn is connected to a holding tube.

Should temperature changes be recorded and passed on quickly fast-responding electrical thermometers that respond to such temperature changes are required react quickly. In practice, this is achieved through constructions in which the temperature sensor, mostly a measuring resistor, is fixed in a holding tube so that it is with its temperature-sensitive part protrudes directly into the medium to be measured.

With conventional wire measuring resistors, where 5

helical resistance wires on a glass or Ceramic body are applied, this is possible without difficulty / because the temperature-sensitive part such measuring resistors have an extension of several millimeters and therefore in a holding tube without Complication can be attached.

In the case of film measuring resistors in which the resistance layer is designed as a thin metal film, there is

. _c the risk that the ο

temperature-sensitive layer is damaged or covered in such a way that incorrect measurements occur. the Heat dissipation that cannot be completely prevented from the relatively small mass of the sheet resistor on the holding tube also leads to differences between the actual and the thermometer shown Medium temperature.

Compared to wire measuring resistors, sheet resistors „ _{5 are} much more sensitive to breakage, so that they are

must be protected from mechanical influences in a holding tube. This can be achieved, for example, through the arrangement of a perforated protective tube over the sheet resistor, which increases the response time of the QQ thermometer increased impermissibly.

It was therefore the task of the present innovation to create a fast-responding electrical thermometer, consisting of a sheet resistor with supply

the inside of a sleeve from a well-heat-5

conductive material is fastened flush with the bottom of the sleeve by means of a potting compound, which in turn is connected to a holding tube. This thermometer should temperature changes rapidly without temperature distortions show and be unbreakable.

This object has been achieved according to the innovation in that an intermediate layer between the sleeve and the holding tube made of a poorly thermally conductive material

is arranged and sleeve and holding tube by means of an Ib

or several constrictions are connected to one another.

The electrical leads to the sheet measuring resistor are preferably in the interior of the holding tube and the sleeve surrounded by an insulating tube * ", the end of which tapered in the wall thickness rests on the casting compound of the sheet resistor. One achieves through it better insulation of the supply lines and the possibility of using the thermometer at higher temperatures .

As an intermediate layer between the holding tube and the sleeve, plastic hoses and potting compounds on synthetic resins are used and ceramic base proven.

The figure shows schematically an exemplary embodiment of the thermometer according to the innovation in longitudinal section. It consists of a sleeve (1)

a material that conducts heat well, such as silver, copper 5

or steel, which has an intermediate layer (5) in the form of a polytetrafluoroethylene hose with the holding tube (4) is connected and fastened by means of a constriction (6). At the bottom of the sleeve (1) is a

Sheet resistor (2) by means of a pre-casting compound (3) 10

lying flat and therefore attached with good heat conductivity.

The intermediate layer (5) and advantageously also the holding tube (4) consist of a poorly thermally conductive Material. This will cause heat to flow away from

the sleeve (1) largely prevented. The supply lines 15

(8) are inside the holding tube (4) and the sleeve

(1) surrounded by an insulating tube (7) which rests on the sealing compound (3) with a tapered wall thickness. These Tapering reduces the heat flow from the layer measuring

resistance (2) on the insulating tube (7). 20th

The electric thermometers according to the innovation respond very quickly to changes in temperature and show unadulterated ones Temperatures are unbreakable and can also be used to display the temperature in moist gases or be used in liquids.

Claims (3)

-::. : 83 170 et PAT / Dr.Br-Ca May 26, 1983 Degussa Aktiengesellschaft Weissfrauenstrasse 9 6000 Frankfurt am Main 1 10 Fast-responding electrical thermometer Protection claims ί: 15 1. Quick-response electrical thermometer, consisting of ι i from one ': film resistor with leads, % of the inside ": n a sleeve made of a good heat-insulating £ 20 ί tending material by means of a casting compound on the floor |; the sleeve is fastened flat, which its- ".. is connected on the one hand with a holding tube, then i; characterized in that between the sleeve (1) and r the holding tube (4) from an intermediate layer (5) ; 25th f 'arranged a poorly thermally conductive material is and sleeve (1) and holding tube (4) by means of one or more constrictions (6) with one another are connected. 30th 2. Fast acting electrical thermometer according to claim 1, characterized in that the electrical leads (9) from an insulating tube (7) are surrounded, the end of (8) in the wall thickness 35 is tapered and rests on the casting compound (3) of the sheet resistor (2). 3. Fast-responding electrical thermometer according to claim 2, characterized in that the Intermediate layer (5) made of a plastic tube or a potting compound based on synthetic resin or ceramic consists.