A vibration measurement system for deaf people’s emergency apparatus

A vibration measurement system for deaf people’s emergency warning equipment is presented in this paper. Deaf alarm devices are among the most supportive products that help to alert deaf people in various emergency circumstances. Applicable British standards recommend that acceptable working parameters for such products are frequency: 25 to 150 Hz, enough vibration strength, intensity and stable performance against lifetime. This paper presents research that has been conducted to test and validate the performance of a variety of alerting devices using the proposed vibration measurement system. It introduces the laboratory arrangements, practical measurements carried out and its compliance with the British standards. The products investigated were the Mk I, Mk II Deaf Alerters, the Deafgard alerting device and the C-TEC 24V Pillow Pad. Measurements were taken using an ADXL335 accelerometer, to determine the vibration strength. Other parameters considered were temperature variation, efficiency and lifetime of the products.