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Networked fume hood monitoring system

  • US 5,439,414 A
  • Filed: 07/26/1993
  • Issued: 08/08/1995
  • Est. Priority Date: 07/26/1993
  • Status: Expired due to Term
First Claim
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1. Apparatus for monitoring the operation of a fume hood which is operable to maintain a flow of air through the fume hood, including any uncovered portion of an opening of a fume hood of the type which has at least one moveable sash door adapted to selectively cover and uncover the opening during movement thereof, the fume hood being in communication with an exhaust duct for expelling air and fumes from the fume hood, the fume hood being located in a building having a supervisory control system for controlling the building heating, ventilating and air conditioning equipment, said apparatus being adapted to generate signals that are indicative of the monitored operation, said apparatus comprising:

  • velocity sensing means for measuring the flow of air through the fume hood and generating a flow signal that is indicative of the flow of air through the fume hood;

    an alarm means and a switch of expelling said alarm means if said alarm means is activated;

    processing means for generating a face velocity signal indicative of the average face velocity responsive to said flow signal;

    said processing means being adapted to generate an identification signal which identifies the fume hood which the apparatus is monitoring during operation;

    said processing means including means for specifying a bandwidth defined by a predetermined minimum face velocity signal and a predetermined maximum face velocity signal;

    said processing means being adapted to generate an alarm signal responsive to said face velocity signal being outside of said bandwidth;

    said processing means being adapted to generate an alarm acknowledgement signal responsive to an operator actuating said alarm expel switch;

    means for communicating said identification signal, said face velocity signal, any alarm signal and any alarm acknowledgement signal to the building supervisory control system.

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