0.1 TO 1.0 PSI OVER FREQUENCY RANGE 10 HZ TO 5KHZ

A PORTABLE ELECTROACOUSTIC CALIBRATION TEST SET TO PERMIT THE CONVENIENT CALIBRATION OF DYNAMIC PRESSURE MEASUREMENT OVER THE PRESSURE RANGE 0.1 OS1 AND OVER THE FREQUENCY RANGE 10 HZ TO 5 KHZ WILL BE COMPLETELY DESIGNED DURING PHASE I. THE TEST CHAMBER WILL COMPRISE A RIGID WALLED ENCLOSURE OF MINIMUM VOLUME WITH A MAXIMUM LINEAR DIMENSION OF 5\8" TO PREVENT STANDING WAVES AT 5 KHZ. A REFERENCE STANDARD MICROPHONE WILL BE DESIGNED TO BE INSERTED THROUGH THE WALL OF THE TEST CHAMBER FOR THE PURPOSE OF MONITORING THE PLRESSURE GENERATED IN THE CAVITY BY A TRANSMITTING TRASDUCER THAT WILL BE OF THE TEST CHAMBER. THE TRANSMITTING TRANSDUCER WHEN DRIVENFROM A VARIABLE FREQUENCY OSCILLATOR WILL GENERATE ANY DESIRED SOUND PESSURE UP TO AT LEAST 1 OSI AT ANY FREQUENCY OVER THE BAND 10 HZ TO 5 KHZ. A THIRD OPENING IN THE CHAMBER WALL WILL RECEIVE THE PRESSURE MEASUREMENT MICROPOHONE WHICH IS TO BE CALIBRATED. THE OUTPUTS FROM THE REFERENCE STANDARD MICROPHONE AND THE MICROPHONE BEING CALIBRATED ARE CONNECTED TO SEPARATE DESIGNATED TERMINALS ON THE PANEL OF A PORTABLE ELECTRONIC CONSOLE THAT WILL CONTAIN THE NECESSARY ELECTRONICS TO COMPARE THE OUTPUT SIGNALS FROM THE REFERENCE STANDARD AND THE MICROPHONE BEING TESTED WILL BE ACCOMPLISHED.