26 ELECTRICAL AND ELECTRONIC MEASUREMENT AND COMMUNICATION MEASUREMENT INSTRUMENTS NAMELY, SOUND LEVEL METERS, VIBRATION MEASURING AND CALIBATING INSTRUMENTS, ACOUSTIC WAVE GENERATORS, SOUND DETECTION SYSTEMS, TELEMETERING SYSTEMS, SOUND ATTENUATING AND VIBRATION DAMPING APPARATUS, SIGNAL MONITORING SYSTEMS INCLUDING CONSOLES FOR THE SAME, METERS, ANALOGUE ELECTRONIC CORRELATORS, AND ELECTRICAL AND ELECTRONIC COMPUTING EQUIPMENT