DIGITALLY MODIFIED RESISTIVE OUTPUT FOR A TEMPERATURE SENSOR

• US 20080195348A1
• Filed: 04/12/2008
• Published: 08/14/2008
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Measurement Specialties, Inc. (France) (TE Connectivity Limited)
• Original Assignee: YSI Incorporated (Xylem, Inc.)
• Inventors: Kill, Robert A., Shidemantle, Jack P.
• Granted Patent: US 7,641,390 B2
• Time in Patent Office: Days
• US Class Current: 702/133
• 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 determining 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 the temperature probe, 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.

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

3. The interface of claim 2, wherein the logic circuit is a microprocessor.

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

5. A temperature probe comprising:

a temperature sensor having a resistive output;

a processor for determining 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 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 determine a modified resistive output;

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

outputting 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.