Richard W Baril

US Patent:

20030132755, Jul 17, 2003

Filed:

Dec 13, 2002

Appl. No.:

10/319430

Inventors:

Chang-Dong Feng - Long Beach CA, US
Joe Covey - Tustin CA, US
Beth Covey - Tustin CA, US
Richard Baril - Huntington Beach CA, US
Roland Koluvek - Orange CA, US

International Classification:

G01N027/416

US Classification:

324/438000

Abstract:

The invention relates to an internal solution ground for primary use with a pH sensor, and preferably with a multi-sensing instrument monitoring a pH sensor and one or more additional secondary sensors having non-isolated circuits. In one aspect, a pH sensor assembly includes a pH electrode, a reference electrode, and an internal solution ground wire. The internal solution ground wire shares a liquid junction with the reference electrode but is protected by the reference fill solution. In one embodiment, the internal solution ground can be electrically isolated through a capacitor or, alternately, a capacitor and resistor in parallel.