Design for a strain gauge target flow meter

Claim 1

IN A DEVICE FOR MEASURING THE FLOW RATE OF GASES MOVING AT LOW VELOCITIES THE COMBINATION COMPRISING A SEMI-RIGID CANTILEVER ARM PARTIALLY ENCLOSED WITHIN A SHIELDING CONCENTRIC MEMBER, SAID ARM HAVING A FREE END WITH A TARGET MOUNTED THEREON EXTENDING OUTSIDE THE SHIELDING MEMBER AND UPON WHICH TARGET MOVING GASES CAN IMPINGE, SAID SHIELDING MEMBER ACTING AS A STOP FOR THE CANTILEVERED ARM TO PROTECT THE DEVICE AGAINST ANY PURGES OF GAS, SAID FREE END OCCUPYING NO MORE THAN ABOUT 0.5 TO 3.0 PERCENT OF THE CROSS-SECTIONAL AREA OF THE CONDUIT, AND A FIXED END CONTIGUOUS TO AND MOUNTED BETWEEN A PAIR OF SEMI-CONDUCTOR GAUGES WITHIN WHICH MECHANICAL STRESSES OF TENSION AND COMPRESSION, RESPECTIVELY, ARE PRODUCED UPON MOVEMENT OF THE FREE END OF THE CANTILEVER ARM BY IMPINGING GASES, SAID GAUGES EACH POSSESSING AN ELECTRICAL RESITIVITY AT ROOM TEMPERATURE RANGING FROM ABOUT 10-2 TO ABOUT 10-9 OHM-CM., AND WHICH GAUGES ARE IN CONTACT WITH AN ELECTRICAL CIRCUIT FOR CONVERTING THE STRESSES PRODUCED INTO AN ELECTRICAL SIGNAL OF INTENSITY PROPORTIONAL TO THE STRAINS TO ACCURATELY MEASURE GAS VELOCITIES ON AN ORDER RANGING AS LOW AS ABOUT 0.1 FT/SEC. TO ABOUT 4.0 FT/SEC., AND CHANGES IN VELOCITY AS LOW AS ABOUT 0.05 FT/SEC.