The new current loop: an instrumentation and measurement circuit topology

Author

Anderson, Karl F.

Author_Institution

Valid Meas., Lancaster, CA, USA

Volume

46

Issue

5

fYear

1997

fDate

10/1/1997 12:00:00 AM

Firstpage

1061

Lastpage

1067

Abstract

A new current loop analog measurement circuit topology is presented that significantly outperforms the classic Wheatstone bridge in many instrumentation, measurement, and control applications. Using active subtraction as the key enabling technology, the new current loop can provide greater accuracy with less excitation power and fewer connecting wires. Several sensor elements can exist in the same current loop with their independent and combined outputs available simultaneously. Measurement functions beyond what an equivalent Wheatstone bridge can provide have been accomplished. The limitations of the Wheatstone bridge are recalled and the new current loop theory is presented along with test data acquired using an elementary single component active subtractor

Keywords

analogue circuits; bridge circuits; high-temperature techniques; network topology; strain measurement; temperature measurement; active subtraction; analog measurement circuit topology; current loop; excitation power; sensor elements; single component active subtractor; test data; Bridge circuits; Circuit topology; Current measurement; Electrical resistance measurement; Impedance; Instrumentation and measurement; Instruments; Joining processes; Strain measurement; Transducers;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.676711

Filename

676711