Thermometer having a diagnostic function

Patent metadata

Field	Value
Publication number	US-12480825-B2
Application number	US-202017757419-A
Country	US
Kind code	B2
Filing date	Dec 1, 2020
Priority date	Dec 16, 2019
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

The present disclosure relates to a method for determining and/or monitoring the temperature of a medium by means of a thermometer having at least one temperature sensor, the method including: determining a measured value for the temperature of the medium by means of a temperature sensor; determining a heat flow, in particular heat dissipation, in the region of the temperature sensor; and determining a measured value deviation for the measured value for the temperature on the basis of a model for heat dissipation in the region of the temperature sensor.

First claim

The invention claimed is:

1 . A method for determining and/or monitoring a temperature of a medium using a thermometer, wherein the thermometer comprises a temperature sensor including a temperature-sensitive sensor element electrically contacted to at least a first connection line and a second connection line,
wherein the first connection line includes a first section and a second section, wherein the first section, which faces the sensor element, comprises a first material, wherein the second section, which faces away from the sensor element, comprises a second material, which differs from the first material, wherein the second connection line comprises the second material, and wherein the first section of the first connection line and at least a portion of the second connection line define a first differential temperature sensor in the form of a thermocouple, the method comprising:
determining a measured value of the temperature of the medium using the temperature sensor;
determining a heat flow, or a variable associated with the heat flow, in a region of the temperature sensor, wherein the heat flow is determined using the first differential temperature sensor; and
determining a measured value deviation for the measured value of the temperature based on a model for the heat flow in the region of the temperature sensor determined by the first differential temperature sensor.

2 . The method of claim 1 , wherein the heat flow is a heat dissipation.

3 . The method of claim 1 , wherein the model is a parametric model comprising at least one static and one dynamic term for determining the measured value deviation.

4 . The method of claim 1 , wherein at least one of the following is incorporated in the model via at least one coefficient of the model: an installation condition or mounting condition of the thermometer on a container containing the medium; a process condition of a process in which the thermometer is applied; a parameter or another characteristic variable relating to the thermometer; a process variable of the medium; a flow rate of the medium; an ambient temperature or an environmental influence for the thermometer; and information about a physical and/or chemical property of the medium.

5 . The method of claim 1 , wherein at least one coefficient of the model is determined using a reference measurement using a reference device in a reference medium.

6 . The method of claim 1 , wherein at least one coefficient of the model is determined analytically or numerically.

7 . The method of claim 6 , wherein a process variable of the medium other than the temperature is a flow rate of the medium.

8 . The method of claim 1 , wherein a state indicator for the thermometer is determined based on the determined measured value deviation.

9 . The method of claim 8 , wherein, in the case of invasive temperature determination and/or monitoring, the state indicator is a statement about an installation condition, an occurrence of corrosion, or a deposit formation and, in the case of non-invasive temperature determination and/or monitoring, the state indicator is a statement about a thermal coupling between the thermometer and a container containing the medium.

10 . The method of claim 8 , wherein the state indicator is a statement about a change of the medium or an exchange of the medium, about a change in a flow rate of the medium, or about a self-heating error in the region of the temperature sensor caused by a self-heating of the temperature sensor.

11 . The method of claim 8 , wherein the state indicator is determined by comparing the determined measured value deviation with a reference value for the measured value deviation.

12 . The method of claim 11 , wherein, when the thermometer is put into operation in a process, the reference value for the measured value deviation is determined experimentally using the process.

13 . The method of claim 11 , further comprising making a statement about the state of the thermometer when a difference between the determined measured value deviation and the reference value exceeds or falls below a predefined limit value.

Assignees

• Endress Hauser Wetzer Gmbh Co Kg

Inventors

• Schalles Marc

Classifications

• G01K7/42

  Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature · CPC title

• G01K7/02 Primary

  using thermoelectric elements, e.g. thermocouples · CPC title

• G01K7/16

  using resistive elements · CPC title

• G01K13/02

  for measuring temperature of moving fluids or granular materials capable of flow · CPC title

• G01K15/005 Primary

  Calibration · CPC title