Thermometry probe calibration method

• US 7,255,475 B2
• Filed: 10/12/2005
• Issued: 08/14/2007
• Est. Priority Date: 10/11/2002
• Status: Expired due to Term

• Current Assignee: Welch Allyn Incorporated
• Original Assignee: Welch Allyn Incorporated
• Inventors: Quinn, David E., Lane, John, Burdick, Kenneth J., Cuipylo, William N., Stone, Ray D.
• Primary Examiner(s): VERBITSKY, GAIL KAPLAN
• Application Number:
  US11/248,492
• Publication Number:
  US 20060072645A1
• Time in Patent Office: 671 Days
• Field of Search: 374/121, 374/120, 374/163, 374/183, 600/474, 600/549, 702/139, 702/99
• US Class Current: 374/163
• CPC Class Codes: G01K 15/005 Calibration
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature

Abstract

A method in which thermal mass and manufacturing differences are compensated for in thermometry probes by storing characteristic data relating to individual probes into an EEPROM for each probe which is used by the temperature apparatus.

Claims

1. A method for calibrating a temperature probe for a thermometry apparatus, said method comprising the steps of:

characterizing the transient heat rise behavior of a temperature probe used with said apparatus;

comparing the characterized transient heat behavior of a said temperature probe to that of a nominal temperature probe and normalizing said characterized transient heat rise behavior based on said comparing step;

storing the normalized transient heat rise behavior on an EEPROM associated with said probe; and

applying the stored normalized transient heat rise behavior to an algorithm for predicting a final steady state temperature for said probe wherein said characterizing step includes the steps of applying a voltage pulse to said probe and plotting temperature rise versus time and in which said comparing and normalizing step includes the step of comparing the plotted temperature rise curve of said probe to a temperature rise curve for a nominal probe at specified time intervals to determine normalizing coefficients for storing in said EEPROM for applying to said predict algorithm.

2. A method for calibrating a temperature probe for a thermometry apparatus, said method comprising the steps of:

forcing the probe to an initial temperature value;

placing the probe in a test fixture that promotes temperature rise of said probe from said initial temperature value at a known rate;

plotting the temperature rise of said probe versus time;

determining coefficients of said probe from said plotted temperature rise versus time data for storing on a EEPROM of said thermometry apparatus; and

applying said coefficients to an algorithm for predicting temperature.

3. The method of claim 2, wherein said placing step includes the step of placing said probe in a dunk test.

4. The method of claim 2, wherein said predict algorithm is (P×

F₁)+F₂−

(((T₁+T₂)×

F₃)−

F₄) wherein each of F₁ F₂ F₃ and F4 are predetermined numerical coefficients, P is the probe temperature, T₁ is the temperature response of said plotted temperature rise of said probe at a first time interval and T₂ is the temperature response of said plotted temperature rise of said probe at a second time interval.