High resolution digital thermometer

US5295746A · kind A · utility

Assignee

• The United States of America as Represented by the Secretary of the Department of Health and Human Services · US

Inventors

• Walter S. Friauf · Bethesda, US
• Thomas R. Clem, Sr. · Silver Spring, US
• Robert L. Berger · Bound Brook, US

Key dates

• Filing date: Feb 5, 1992
• Grant date: Mar 22, 1994
• Expiry date: Feb 5, 2012

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N25/482
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A high resolution digital thermometer capable of measuring temperature differences on the order of several micro-degrees centigrade. The device includes a bridge circuit having two thermistors in series. An output of the bridge circuit feeds a signal to an analog-to-digital convertor via a high gain amplifier. A computer maintains the balance of the bridge circuit to avoid a situation wherein the range of the analog-to-digital convertor would be exceeded.