Chapter 32 Innovative Tester for Underwater Locator Beacon Used in Flight/Voyage Recorder (Black Box)

摘要

All commercial airplanes that carry more than 20 passengers and all sea merchant vessels with sizes above 3000 gross tonnage must be equipped with flight/voyage data recorders or more popularly known as black box. All black boxes aboard those vessels must be equipped with a completely independent ultrasonic sonar finder device called Underwater Locator Beacon (ULB). In case the device is immersed in water due to an accident, this device will emit ultrasonic signal at 37.5 kHz of a certain pattern for 30 days. The chance of finding the vessel (an airplane or a ship) sinking in the ocean is almost solely depend on the working order of this device. The work presented here is about testing the ULB for its performance using simple system by the use of a microprocessor. The tester will check the voltage of the battery inside the ULB, the expected length of usage of the battery, the generation of the ultrasonic signal at 37.5 kHz, and also about the pattern of the signal. The device designed and built will be small and easy to use with good visual and audio feedback to indicate the result of the UTB test. At the termination of this work, a working system to test a ULB on the voltage and also detection of the ultrasonic signal has been built which is small and intelligent. The usage of the system is very simple, just by inserting the ULB into the system and pressing the unit for 5 s, a thorough result of the ULB test is presented on an LCD screen together with a blinking color light emitting diode (LED) and audible sound via buzzer to prove that the ULB under test is in good working order.