Ultrasonic hand-held refrigerant leak detector

Apparatus for detecting contaminants in air comprising:

• a sensor probe including a housing, a pair of ultrasonic transducers mounted within said housing at fixed positions spaced from each other, means forming an air inlet and an air outlet in said housing, a hollow base, a hollow flexible conduit connecting said housing outlet to said base, and a fan within said base for continuously drawing test air through said inlet, housing, conduit and base between said transducers, and
• an elongated electronics enclosure including means for applying ultrasonic energy to one of said transducers and means responsive to energy received at the other of said transducers for determining contaminant level in said test air, means for removably affixing said base to said enclosure to form a unitary assembly, and means on said enclosure for indicating contaminant level to an operator.

Apparatus for detecting contaminants in air comprising:

• a sensor probe including a housing, a pair of ultrasonic transducers mounted within said housing at fixed positions spaced from each other, means forming an air inlet and an air outlet in said housing, a hollow base, a hollow flexible conduit connecting said housing outlet to said base, and a fan within said base for continuously drawing test air through said inlet, housing, conduit and base between said transducers, and
• an elongated electronics enclosure including means for applying ultrasonic energy to one of said transducers and means responsive to energy received at the other of said transducers for determining contaminant level in the test air, means for removably affixing said base to said enclosure to form a unitary assembly, and means on said enclosure for indicating contaminant level to an operator,
• said base being of generally L-shaped construction and being removably affixed to said enclosure along one leg of said L-shaped construction with the other leg projecting along a side edge of said enclosure, said conduit and housing projecting from said other leg, said enclosure having an integral head of generally L-shaped construction opposed of said base, said head having a socket for removably receiving said housing inlet means when said base is affixed to said enclosure.

coupled to said switch means, to said means for automatically sampling at periodical intervals and to said decrease-responsive means, and an inhibit input coupled to said comparing means.

Apparatus for detecting presence of halogen gas in air comprising:

• sensor probe means including a housing having a central axis, a pair of ultrasonic transducers having identical nominal design frequencies mounted at fixed positions coaxially within said housing with radiating surfaces spaced from each other axially of said housing by a distance between 1.0 and 1.5 times ultrasonic wavelength at said nominal design frequency, means forming an air inlet and an air outlet at axially opposed ends of said housing coaxially with said housing, and means for continually drawing test air through said housing between said transducers, and
• an electronics package coupled to said probe and including means for applying ultrasonic energy to one of said transducers, and means responsive to ultrasonic energy received at the other of said transducers for indicating presence of halogen gas in air between said transducers,
• said energy-responsive means comprising means responsive to a decrease in ultrasonic energy at said other of said transducers for indicating presence of halogen gas, while being substantially independent of increase in energy at said other of said transducers and thereby being substantially independent of humidity between said transducers.

Apparatus for detecting presence of halogen gas in air comprising:

• sensor probe means including a housing having a central axis, a pair of ultrasonic transducers having identical nominal design frequencies mounted at fixed positions coaxially within said housing with radiating surfaces spaced from each other axially of said housing by a distance between 1.0 and 1.5 times ultrasonic wavelength at said nominal design frequency, means forming an air inlet and an air outlet at axially opposed ends of said housing coaxially with said housing, and means for continually drawing test air through said housing between said transducers, and
• an electronics package coupled to said probe and including means for applying ultrasonic energy to one of said transducers, and means responsive to ultrasonic energy received at the other of said transducers for indicating presence of halogen gas in air between said transducers,
• said transducers being externally peripherally engaged by said housing, and said inlet and outlet means including a pair of diametrically opposed axially extending grooves in said housing adjacent and external to each said transducer periphery, a first of said pair of grooves being positioned ninety degrees around said housing with respect to the other said pair.