Resistance thermometer

• US 4,516,865 A
• Filed: 05/31/1983
• Issued: 05/14/1985
• Est. Priority Date: 05/31/1982
• Status: Expired due to Fees

• Current Assignee: Sugimori Hideo
• Original Assignee: Sugimori Hideo
• Inventors: Hideo, Sugimori
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Worth, W. Morris
• Application Number:
  US06/499,427
• Time in Patent Office: 714 Days
• Field of Search: 374/114, 374/163, 374/172, 374/173, 374/183, 374/185, 323/364-367, 338/22, 338/25, 338/28, 330/143, 330/254, 330/256
• US Class Current: 374/172
• CPC Class Codes: G01K 7/21 for modifying the output characteristic, e.g. linearising

Abstract

A resistance thermometer in which a temperature sensing resistor is connected in parallel with a series combination consisting of a signal output resistor and a compensating resistor. By choosing the resistance ratio between two resistors to be equal to the ratio of the desired resistance value to the error of the temperature sensing resistor, the output voltage developed on the signal output resistor reflects the voltage expected on the temperature sensing resistor without the resistance error thereof. The temperature sensing resistor and the compensating resistor constitute a circuit unit which is detachable from the rest of the resistance thermometer.

Claims

1. A resistance thermometer comprising:

a temperature sensing circuit unit consisting of a temperature sensing resistor to be subject to a temperature to be measured and a compensating resistor, said temperature sensing resistor and said compensating resistor each having first and second terminals, wherein said first terminals of said temperature sensing resistor and said compensating resistor are connected together so as to comprise a common terminal, and said second terminal of said temperature sensing resistor comprised a current input terminal, and said second terminal of said compensating resistor comprises a signal output terminal;

a current source connected between said current input terminal and said common terminal;

a signal output resistor connected between said current input terminal and said signal output terminal;

wherein the ratio of resistance of said signal output resistor compared with resistance of said compensating resistor is equal to the ratio of desired resistance of said temperature sensing resistor compared with a positive resistance error of said temperature sensing resistor.