Method and device for monitoring vapor concentration at a phase interface
AssigneeMinnesota Mining and Manufacturing Company
InventorThomas Ian Bradshaw
Life of this patent
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Abstract
Method of monitoring and indicating the concentration of vapor components at a phase interface comprising sampling vapor at the vapor source phase interface, comparing the vapor concentration in the sample with a standard, and indicating the concentration of the vapor relative to the standard. A monitoring device is disclosed which comprises a sensing means and means for responsively coupling the sensing means to the vapor source phase to be monitored so that a representative vapor sample is presented to the sensing means. The method and device disclosed herein can be advantageously used to monitor volatile components, especially moisture, available to potted plants.
Claims17
A device for monitoring and indicating the concentration of a vapor at a phase interface comprising
- a. a sensing means for comparing the concentration of a selected vapor component in a sample with a standard which is representative of a selected parametric concentration of said vapor in said sample, said sensing means including means for indicating the concentration of said vapor in said sample relative to said standard, and
- b. a differentially vapor permeable, liquid impermeable envelope enclosing said sensing means to responsively couple said sensing means to a vapor source phase at said phase interface, said envelope comprising a base adapted to rest on said vapor source phase and a cover for said base, said base and said cover vapor permeable defining a sealed, closely conforming envelope containing said sensing means, said cover having a vapor transmission rate equivalent to a water vapor transmission rate of between 20 and 60 grams/1000 cm.sup.2 /24 hours, said base having a vapor transmission rate at least 50% greater than the vapor transmission rate of said cover, said cover adapted for viewing said indicating means.
A method of continuously monitoring the concentration of vapor at a phase interface which comprises
- a. continuously collecting a representative vapor sample in a differentially vapor permeable, liquid impermeable, envelope directly from a vapor source phase at the phase interface, said envelope comprising a base and a cover vapor permeable, said cover having a vapor transmission rate equivalent to a water vapor transmission rate of between 20 and 60 grams/1000 cm.sup.2 /24 hours;
- b. comparing the concentration of a selected vapor component in said sample with a standard contained in said envelope which is representative of a selected parametric concentration of said vapor in said sample;
- and
- c. visibly indicating the concentration of said vapor in said sample relative to said standard.
Dependencies are inferred from the claim text.