Abstract: A protocol adaptive, computer controlled target-analyte permeation testing instrument, capable of self-adaptive adjustments to measurement interval, rezero frequency and independent zero go-no-go.

Abstract: A protocol adaptive, computer controlled target-analyte permeation testing instrument, capable of self-adaptive adjustments to measurement interval, rezero frequency and independent zero go-no-go.

Abstract: A sensor for detecting a target analyte in a gaseous sample at ultra-low concentrations wherein access opening(s) provided through the sensor housing are plugged with endcap(s) and spent gas (i.e., gaseous sample post detection) is channeled along the interface between the sensor housing and the endcap(s) prior to venting of the spent gas, for flushing any environmentally introduced target analyte from this interface.

Abstract: A method for measuring the transmission rate of an analyte through a film. The method includes the steps of (i) separating a chamber into a first cell and a second cell with a known area of a film, (ii) flushing the first cell with an inert gas to remove any target analyte from the first cell, (iii) introducing a gas containing a known concentration of an analyte into the second cell, (iv) sealing the first cell to gas flow through the first cell, and (v) sensing any analyte in the first cell with a sensor that consumes the analyte at a rate greater than the rate at which the analyte is passing through the film, until a steady state rate of analyte consumption is measured by the sensor.

Abstract: A calibration card and method of using the card to calibrate an analytical instrument capable of reading a photoluminescent oxygen probe. The card includes at least (a) a first mass of an oxygen sensitive photoluminescent dye retained within a hermetically sealed space so as to isolate the dye from environmental oxygen, and in fluid communication with an activated metal-air battery whereby any oxygen permeating into the hermetically sealed space is quickly consumed by the battery, and (b) a second mass of an oxygen sensitive photoluminescent dye in fluid communication with the environment whereby the second mass of photoluminescent dye is exposed to an environmental concentration of oxygen.

Abstract: A valve system that includes (i) first and second longitudinally facing members defining a gap therebetween in fluid communication with transversely offset first and second orifices through the members, (ii) a primary biasing means longitudinally biasing the members away from one another, (iii) an elastic element positioned within the gap between the first and second orifices, and (iv) a repositioning means for longitudinally repositioning one of the members towards the other member against the bias of the primary biasing means for adjusting the longitudinal height of the gap. The members can be repositioned between (a) a first position wherein the elastic element does not seal the gap so as to allow fluid flow from the first orifice to the second orifice through the gap, and (b) a second position wherein the elastic element is compressed between the members and seals the gap so as to prevent fluid flow from the first orifice to the second orifice through the gap.

Abstract: A humidity control system for an analyte permeation testing instrument. The system includes (i) an analyte permeation testing instrument, (ii) a sensor for sensing a target analyte, (iii) a humidity control chamber, and (iv) a selectively permeable membrane permeable to water vapor and impermeable to the target analyte. The analyte permeation testing instrument defines a testing chamber operable for engaging a test film such that the testing chamber is sealingly separated by the test film into a first cell and a second cell throughout a permeation testing period. The sensor is placed in fluid communication with the first cell. The humidity control chamber is positioned adjacent the first cell and in fluid communication with both a source of gas having a known humidity and the first cell, with the selectively permeable membrane sealingly separating the humidity control chamber from the first cell.

Abstract: A calibration card and method of using the card to calibrate an analytical instrument capable of reading a photoluminescent oxygen probe. The card includes at least (a) a first mass of an oxygen sensitive photoluminescent dye retained within a hermetically sealed space so as to isolate the dye from environmental oxygen, and in fluid communication with an activated metal-air battery whereby any oxygen permeating into the hermetically sealed space is quickly consumed by the battery, and (b) a second mass of an oxygen sensitive photoluminescent dye in fluid communication with the environment whereby the second mass of photoluminescent dye is exposed to an environmental concentration of oxygen.

Abstract: A method for measuring the transmission rate of an analyte through a film. The method includes the steps of (i) separating a chamber into a first cell and a second cell with a known area of a film, (ii) flushing the first cell with an inert gas to remove any target analyte from the first cell, (iii) introducing a gas containing a known concentration of an analyte into the second cell, (iv) sealing the first cell to gas flow through the first cell, and (v) sensing any analyte in the first cell with a sensor that consumes the analyte at a rate greater than the rate at which the analyte is passing through the film, until a steady state rate of analyte consumption is measured by the sensor.

Abstract: A humidity control system for an analyte permeation testing instrument. The system includes (i) an analyte permeation testing instrument, (ii) a sensor for sensing a target analyte, (iii) a humidity control chamber, and (iv) a selectively permeable membrane permeable to water vapor and impermeable to the target analyte. The analyte permeation testing instrument defines a testing chamber operable for engaging a test film such that the testing chamber is sealingly separated by the test film into a first cell and a second cell throughout a permeation testing period. The sensor is placed in fluid communication with the first cell. The humidity control chamber is positioned adjacent the first cell and in fluid communication with both a source of gas having a known humidity and the first cell, with the selectively permeable membrane sealingly separating the humidity control chamber from the first cell.

Abstract: A method of measuring the transmission rate of a permeant through a container and determining shelf life of product within the container based upon loss of the permeant through the container. The method includes the steps of (i) placing a sealed container containing a perishable product and a permeant within a sealed retention chamber, (ii) periodically measuring concentration of the permeant within the headspace of the retention chamber until a substantially steady state increase in permeant concentration within the headspace is sensed, and (iii) calculating a shelf life for the sealed container by dividing an amount of permeant loss, previously established as correlating to product expiration, by the sensed steady state increase in permeant concentration.

Abstract: A sensor for detecting water vapor in a gaseous sample. The sensor comprises (a) an anode, (b) a cathode, (c) an electrolyte intermediate the anode and cathode, and (d) an inlet orifice through a central area of the anode or cathode through which the gaseous sample may be placed into contact with the electrolyte. The electrolyte can be retained on a porous electrical-insulating separator located between the interior-facing major surfaces of the anode and the cathode.

Abstract: A needle valve with a hollow needle effective for permitting a portion of the fluid passing through the valve to flow throughout the valve and exit through any leaks in the valve, whereby any environmental fluid within the valve is displaced by the fluid passing through the valve.

Abstract: A galvanic measuring device for detecting oxygen content in a gas flow, having a sealed gas flow chamber and a layer of sodium chloride saturated sponge material lining the interior of the gas flow chamber, for providing a constant source of humidity to the chamber.

Abstract: A process for measuring the vapor transmission rate characteristics of a test material by first measuring the vapor transmission through a test chamber and sample material and subsequently repeating the measurement with the test material adjacent the sample material. By subtracting the first measured transmission rate reciprocal from the second measured transmission rate reciprocal, a value is determined which is the reciprocal of the vapor transmission rate characteristic of the test material.

Abstract: An apparatus for measuring the gas transmission rate through contact lens material, and a method of measuring, using a test cell having an upper and lower gas chamber and separating the upper and lower chamber with a layered group of films, including a contact lens film material clamped between an upper and lower guard film, and flowing oxygen through the upper chamber and an inert gas through the lower chamber, the lower chamber being connected to a coulometric sensor to measure oxygen content in the inert gas at defined intervals, to obtain a first series of oxygen transmission rates. A second series of oxygen transmission rates are made with the same apparatus, but with the contact lens material removed from the apparatus, and the transmission rate through the contact lens material is calculated by subtracting the reciprocal of the second measured transmission rate from the reciprocal of the first measured transmission rate, then taking the reciprocal of the difference.

Abstract: An oxygen sensor constructed as a coulometric sensor and capable of detecting oxygen concentrations in the range of 1% or greater concentrations. The coulometric sensor utilizes a gas flow path which has a predetermined section constructed with oxygen-permeable tubing, wherein a portion of the oxygen flowing through the gas flow path will permeate into the sensor to generate an electric current flow indicative of the permeating oxygen level. The length of the tubing section which is constructed from oxygen-permeable material maybe selectively adjusted to control the relative attenuation of oxygen flow through the sensor.

Abstract: A method for reactivating and recovering electrolyte cells by drilling a hole through the battery case and injecting a volume of electrolyte liquid into the case for absorption into the cell separator material. The battery is subjected to multiple charge/discharge cycles while the cell opening remains unsealed, and is subjected to a final charge prior to sealing the drilled hole through the cell outer case.