US 5,516,489 AGranted

Apparatus for testing peroxide concentrations in sterilants

AssigneeDespatch Industries, Inc.

InventorsHans L. Melgaard, Louis A. Larson

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Abstract

An apparatus for testing peroxide concentration in a gaseous sterilant. A preferred embodiment of the apparatus includes a condenser for condensing the gaseous sterilant into a liquid condensate; an aliquot collector of predetermined volume to receive the condensate; a reaction chamber containing a catalyst for dissociating the peroxide; and a pressure monitor for detecting pressure changes in the reaction chamber as a function of time. The pressure monitor of this apparatus is capable of detecting a threshold pressure and an upper pressure and it includes a timer to measure time change between detection of the threshold pressure and the upper pressure.

Claims13

Dependent claims

An apparatus for measuring peroxide concentration in a gaseous sterilant, comprising:

a. a condenser for condensing the gaseous sterilant into a liquid condensate;
b. a collection and testing tube disposed beneath the condenser;
c. a first valve disposed along the tube toward the condenser, the first valve having an open position and a closed position for selectively blocking flow through the tube;
d. a second valve disposed along the tube at a location below the first valve having an open position and a closed position for selectively blocking flow through the tube, the first and second valves being spaced away from one another to define therebetween an aliquot collector of predetermined volume when the first and second valves are in their closed positions;
e. a third valve disposed along the tube at a location below the second valve having an open position and a closed position for selectively blocking flow through the tube, the second and third valves being spaced away from one another to define therebetween a reaction chamber of predetermined volume when the second and third valves are in their closed positions;
f. a catalyst for dissociating said peroxide in said aliquot, the catalyst being carried within the tube at a location disposed between the second and third valves;
g. a pressure monitor operatively connected to the reaction chamber for detecting pressure changes resulting from said dissociation as a function of time, which pressure change is correlated to the concentration of peroxide in said sterilant, the pressure monitor including a timer and means for detecting a threshold pressure and an upper pressure, the pressure monitor being adapted to measure time change on the timer between detection of the threshold pressure and detection of the upper pressure;
and
h. a microprocessor operatively connected to the pressure monitor for calculating a peroxide concentration from said time change and a display for displaying the calculated peroxide concentration.

6 more elements

Dependencies are inferred from the claim text.

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Abstract

An apparatus for measuring peroxide concentration in a gaseous sterilant, comprising:

a. a condenser for condensing the gaseous sterilant into a liquid condensate;
b. a collection and testing tube disposed beneath the condenser;
c. a first valve disposed along the tube toward the condenser, the first valve having an open position and a closed position for selectively blocking flow through the tube;
d. a second valve disposed along the tube at a location below the first valve having an open position and a closed position for selectively blocking flow through the tube, the first and second valves being spaced away from one another to define therebetween an aliquot collector of predetermined volume when the first and second valves are in their closed positions;
e. a third valve disposed along the tube at a location below the second valve having an open position and a closed position for selectively blocking flow through the tube, the second and third valves being spaced away from one another to define therebetween a reaction chamber of predetermined volume when the second and third valves are in their closed positions;
f. a catalyst for dissociating said peroxide in said aliquot, the catalyst being carried within the tube at a location disposed between the second and third valves;
g. a pressure monitor operatively connected to the reaction chamber for detecting pressure changes resulting from said dissociation as a function of time, which pressure change is correlated to the concentration of peroxide in said sterilant, the pressure monitor including a timer and means for detecting a threshold pressure and an upper pressure, the pressure monitor being adapted to measure time change on the timer between detection of the threshold pressure and detection of the upper pressure;
and
h. a microprocessor operatively connected to the pressure monitor for calculating a peroxide concentration from said time change and a display for displaying the calculated peroxide concentration.

6 more elements