Digitally modified resistive output for a temperature sensor

• US 7,641,390 B2
• Filed: 04/12/2008
• Issued: 01/05/2010
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Measurement Specialties Incorporated (TE Connectivity Limited)
• Original Assignee: YSIS, Inc.
• Inventors: Kill, Robert A., Shidemantle, Jack P.
• Primary Examiner(s): Verbitsky; Gail
• Assistant Examiner(s): Jagan; Mirellys
• Application Number:
  US12/101,962
• Publication Number:
  US 20080195348A1
• Time in Patent Office: 633 Days
• Field of Search: 374/168, 374/183, 374/185, 374/169, 374/1, 702/107, 702/99, 702/104, 702/90, 702/91, 702/133
• US Class Current: 374/183
• CPC Class Codes: G01K 7/25 for modifying the output characteristic, e.g. linearising
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature

Abstract

A method for digitally controlling the resistive output of a temperature probe is disclosed. The system is comprised of a temperature sensor, a processor and a means under the control of the processor for modifying the resistive output such as a digital potentiometer. In one embodiment, the processor reads the temperature sensor and adjusts the potentiometer based on a correlative or predictive technique so as to provide a modified output that matches that of a standard resistive temperature probe and is compatible for display on a multi-parameter monitor.

Claims

1. An interface for a monitor and a temperature probe including a temperature sensor, said interface comprising:

a logic circuit for modifying a resistive output of the temperature sensor to determine a modified resistive output for the temperature sensor; and

a means for providing the modified resistive output, wherein the means for providing the modified resistive output is compatible with the monitor such that the monitor can display a temperature that corresponds to the modified resistive output from said means, said means including a digital potentiometer,

wherein the logic circuit sends a control signal to the digital potentiometer such that the potentiometer provides the modified resistive output to the monitor.

2. The interface of claim 1, wherein the means for providing the modified resistive output includes two digital potentiometers.

3. The interface of claim 1, wherein the logic circuit is programmed to execute a predictive or a correlative algorithm.

4. The interface of claim 3, wherein the logic circuit is a microprocessor.

5. A temperature probe comprising:

a temperature sensor having a resistive output;

a processor for modifying the resistive output of the temperature sensor to determine a modified resistive output for the temperature sensor, the processor being programmed to execute a predictive or a correlative algorithm; and

a digital potentiometer for providing the modified resistive output to a monitor in response to a signal from the processor,

wherein the algorithm converts the resistive output of the temperature sensor during a thermally unstable condition to a modified resistive output representative of a predicted temperature during a condition of thermal stability.

6. The temperature probe of claim 5, wherein the probe includes two digital potentiometers.

7. A method for digitally modifying the resistive output of a temperature sensor, said method comprising the steps of:

inputting the resistive output from the temperature sensor to a logic circuit;

implementing a predictive or a correlative algorithm using the logic circuit to modify the resistive output to determine a modified resistive output; and

signaling a digital potentiometer to adopt a setting corresponding to the modified resistive output;

wherein the digital potentiometer outputs a resistance corresponding to the modified resistive output.

8. The method of claim 7, wherein the signaling step comprises signaling two digital potentiometers to adopt a setting corresponding to the modified resistive output.