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US 5,396,178 AGranted
Apparatus and method for determining that equipment is clean
AssigneeDober Chemical Corporation
InventorRobert J. Rybarski
Life of this patent
Estimating the term…
Abstract
Apparatus and methods for determining that a piece of equipment, for example, used in the biotechnology or pharmaceutical industries, is clean are disclosed. The invention involves measuring the electrical conductivity of an aqueous liquid medium both before and after the medium is used to contact, e.g., rinse, the piece of equipment. The equipment is determined to be clean when these two measured electrical conductivities are substantially equal.
Claims20
A method for determining that a piece of equipment is clean which comprises:
- (a) causing an aqueous liquid rinse medium to come into contact with said piece of equipment;
- (b) determining the electrical conductivity of said aqueous liquid medium prior to said aqueous liquid rinse medium being used in step (a);
- (c) determining the electrical conductivity of said aqueous liquid rinse medium after said aqueous liquid rinse medium is used in step (a);
- and
- (d) comparing the electrical conductivities determined in steps (b) and (c), said piece of equipment being determined to be clean when said electrical conductivity determined in step (c) substantially equals said electrical conductivity determined in step (b).
2 more elements
An apparatus for determining that a piece of equipment is clean which comprises:
- a first conductivity meter assembly located with respect to the piece of equipment to measure the electrical conductivity of an aqueous liquid rinse medium prior to the aqueous liquid rinse medium being used to contact the piece of equipment and to provide a first signal indicative of said electrical conductivity measured by said first conductivity meter assembly;
- a second conductivity meter assembly located with respect to the piece of equipment to measure the electrical conductivity of the aqueous liquid rinse medium after the aqueous liquid rinse medium is used to contact the piece of equipment and to provide a second signal indicative of said electrical conductivity measured by said second conductivity meter assembly;
- and
- a signal comparing assembly located so as to receive both said first signal and said second signal, said signal comparing assembly being structured to compare said first signal and said second signal and to provide a third signal when said electrical conductivity measured by said second conductivity meter assembly substantially equals said electrical conductivity measured by said first conductivity meter assembly, said third signal being indicative that said piece of equipment is clean.
1 more element
Dependencies are inferred from the claim text.