Back to results
US 4,375,667 AGranted
Personal air sampling system
OwnerRoy M. Buchaninventor
Life of this patent
Estimating the term…
Abstract
A thermal anemometer is employed to detect the velocity of the air flowing through a personal air sampling device. A microprocessor system is employed to periodically read the signal from the thermal anemometer and calculate the sample air flow rate. The measured flow rate is integrated over the sample period to provide an indication of the total volume of air sampled. Flow rates need not be calibrated during the sample period to insure accurate collection data, thus providing an automated and accurate means for measuring air quality.
Claims11
A personal air sampling device which comprises:
- a housing defining an air passageway having an air intake and an exhaust;
- an air pump mounted to the housing for pumping air through the air passageway;
- an air contaminant collection device connected to collect material in the air flowing through the air passageway;
- air velocity sensor means mounted to the housing and being operable to generate a signal indicative of the velocity of the air passing through the air passageway;
- converter means coupled to the velocity sensor means for periodically reading the velocity sensor signal and converting it to a digital velocity number indicative of the velocity of the air passing through the air passageway;
- first calculation means coupled to the converter means for receiving said digital velocity number and calculating an incremental air flow volume number which is indicative of the volume of air flowing through the air passageway during a preset time increment;
- second calculation means coupled to the first calculation means for adding together each calculated incremental air flow volume number to form a total air volume number;
- and
- display means coupled to the second calculation means to receive the total air volume number and provide a visual indication of that number.
6 more elements
A personal air sampling device which comprises:
- a housing which defines an air passageway through which sampled air flows;
- an air contaminant collection device connected to the air passageway to collect material in the sampled air;
- an air pump mounted to the housing for pumping sample air through the air passageway;
- a thermal anemometer disposed in the air passageway and operable to generate an analog electrical signal indicative of the velocity of the sample air flowing through the air passageway;
- an analog to digital converter circuit connected to receive the analog signal generated by the thermal anemometer and convert it to a digital number indicative of sample air velocity;
- digital processor means coupled to said analog to digital converter circuit and being operable to periodically read the digital air velocity number generated by said analog to digital converter and calculate a total air volume number therefrom which indicates the total sample air flowing through the air passageway during a sample period;
- and
- a display coupled to the digital processor means for providing a visual indication of the total air volume number.
5 more elements
A personal air sampling device which comprises:
- a housing defining an air passageway having an air intake and an exhaust;
- an air pump mounted to the housing for pumping sampled air through the air passageway;
- a tube connected to the housing to transport sampled air to the air intake of said air passageway;
- an air contaminant collection device connected to the tube and positioned to collect material in the sampled air transported by the tube;
- air velocity sensor means mounted to the housing and being operable to generate a signal indicative of the velocity of the air passing through the air passageway;
- converter means coupled to the velocity sensor means for periodically reading the velocity sensor signal and converting it to a digital velocity number indicative of the velocity of the air passing through the air passageway;
- first calculation means coupled to the converter means for receiving said digital velocity number and calculating an incremental air flow volume number which is indicative of the volume of air flowing through the air passageway during a preset time increment;
- second calculation means coupled to the first calculation means for adding together each calculated incremental air flow volume number to form a total air volume number;
- and
- display means coupled to the second calculation means to receive the total air volume number and provide a visual indication of that number.
7 more elements
Dependencies are inferred from the claim text.