Temperature probe and method for manufacturing a temperature probe

Patent metadata

Field	Value
Publication number	US-12352636-B2
Application number	US-202218066431-A
Country	US
Kind code	B2
Filing date	Dec 15, 2022
Priority date	Dec 16, 2021
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A temperature probe for determining the temperature according to the three-point probe method includes a three-wire line several meters long consisting of a first connecting line, a second connecting line, and a third connecting line connected to sensor element. The connecting lines are made of a first material and serve to transmit energy and the measured temperature values. A conductive element made of a second material is inserted in the second connecting line and in the third connecting line. The resistivity of said second material is higher than the resistivity of the first material. The two inserted conductive elements are designed such that the second connecting line and the third connecting line have the same resistance as the first connecting line. Additionally, the present disclosure refers to a method describing the manufacture of a temperature probe.

First claim

The invention claimed is:

1. A temperature probe for determining a temperature according to a three-point probe method, the temperature probe comprising:
a sensor element embodied to provide temperature values;
a three-wire line several meters long, the three-wire line including:
a first connecting line;
a second connecting line; and
a third connecting line,
wherein the three-wire line is connected to the sensor element, and
wherein each of the three connecting lines is made of a first material and serves to transmit energy and measured temperature values;

a first conductive element made of a second material and inserted in the second connecting line; and
a second conductive element made of the second material and inserted in the third connecting line,
wherein a resistivity of the second material is higher than a resistivity of the first material, and
wherein the two inserted conductive elements are designed such that the second connecting line and the third connecting line have a same resistance as the first connecting line.

2. The temperature probe according to claim 1 ,
wherein the resistivity of the second material is at least 5 times higher than the resistivity of the first material.

3. The temperature probe according to claim 2 ,
wherein the three connecting lines are made of copper, and wherein the two inserted conductive elements are made of constantan.

4. The temperature probe according to claim 1 ,
wherein the two inserted conductive elements made of the second material are arranged within a bushing where two sections of the three-wire line are interconnected.

5. The temperature probe according to claim 1 ,
wherein the two conductive elements made of the second material are arranged in a connection area via which the three-wire line is connectable to external electronics.

6. The temperature probe according to claim 1 ,
wherein the resistance of the two conductive elements inserted in the second connecting line and in the third connecting line is designed such that the temperature probe provides measured values with a predetermined measurement accuracy.

7. The temperature probe according to claim 1 ,
wherein the sensing element is a Resistance Temperature Detector (RTD) element.

8. A method of manufacturing a temperature probe for determining a temperature according to a three-point probe method with a sensor element designed as a platinum measuring resistor that provides temperature measured values, wherein a three-wire line several meters long having a first connecting line, a second connecting line, and a third connecting line is associated with the sensor element, wherein the three connecting lines are made of a first material with a predetermined specific resistance and serve for transmitting energy and for transmitting the measured temperature values, the method comprising:
measuring a resistance of each of the three connecting lines;
determining a connecting line having the highest resistance, hereinafter: the first connecting line;
inserting a first conductive element into the second connecting line, wherein the first conductive element is made of a second material having a resistivity greater than the resistivity of the first material, and wherein the inserted first conductive element is dimensioned such that the second connecting line has the same resistance as the first connecting line;
inserting a second conductive element into the third connecting line, wherein the second conductive element is made of the second material, and wherein the inserted second conductive element is dimensioned such that the third connecting line has the same resistance as the first connecting line.

9. The method according to claim 8 ,
wherein the two conductive elements are welded, brazed, soldered, or crimped for insertion into the corresponding connecting lines.

10. The method according to claim 8 ,
wherein the inserted conductive elements made of the second material are arranged within a bushing where two sections of the three-wire line are interconnected.

11. The method according to claim 8 ,
wherein the inserted conductive elements made of the second material are arranged in a connection area via which the three-wire line is connectable to external electronics.

12. The method according to claim 8 ,
wherein the conductive elements made of the second material and corresponding wire connections connecting the conductive elements to the wires are protected by an encapsulation box, whereby the conductive elements protected by the encapsulation box are inserted in a flexible extension cable.

Assignees

• Endress Hauser Wetzer Gmbh Co Kg

Inventors

• Bini Christian
• Ahmed Shakil
• Del Bianco Massimo

Classifications

• H01R2201/20

  for testing or measuring purposes · CPC title

• H01R11/18

  End pieces terminating in a probe · CPC title

• H01B5/02

  Single bars, rods, wires, or strips · CPC title

• G01K2217/00

  Temperature measurement using electric or magnetic components already present in the system to be measured · CPC title

• G01K1/08

  Protective devices, e.g. casings · CPC title