Indicating system for atmospheric pump arrangement
First Claim
1. In an atmospheric sampling pump arrangement, the combination of a mass flow sensor for producing an output signal proportional to mass airflow of atmospheric air, means for comparing said output signal with a set-point voltage to produce a signal voltage when mass airflow drops below a predetermined limit, means for indicating the existence of said signal voltage, a counter, means for enabling said counter to count up when said signal voltage exists, and second indicating means which is actuated when said counter counts up to a predetermined value.
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Accused Products
Abstract
An atmospheric sampling pump arrangement employing a mass flow sensor which electronically monitors mass flow and compares it to a set-point value. The pump is then controlled in a manner that will minimize the difference between the measured flow and the set-point value. When the flow output drops below a predetermined value, a signal is energized to indicate the inability to maintain the desired flow. The system also incorporates a timer circuit which counts up the total amount of time that loss of flow regulation exists. After a predetermined period of cumulative loss of flow regulation, typically 30 minutes, a signal is energized to indicate this condition.
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Citations
8 Claims
- 1. In an atmospheric sampling pump arrangement, the combination of a mass flow sensor for producing an output signal proportional to mass airflow of atmospheric air, means for comparing said output signal with a set-point voltage to produce a signal voltage when mass airflow drops below a predetermined limit, means for indicating the existence of said signal voltage, a counter, means for enabling said counter to count up when said signal voltage exists, and second indicating means which is actuated when said counter counts up to a predetermined value.
Specification