Bruel And Kjaer Helps To Test Lift Sound Quality

Orona has used Bruel and Kjaer's Head and Torso Simulator (HATS), binaural microphones and Pulse sound-quality software to analyse the sound-quality behaviour of its lifts. This equipment allowed it to correlate the sound quality with the different noise sources and to study the most appropriate ways to improve lift comfort. Orona (manufacturer of lifts), Mondragon Goi Eskola Politeknikoa (MGEP [Engineering Faculty of Mondragon University]) and Ikerlan (Research Centre) formed a consortium to investigate the sound quality in Orona's lifts.

According to Unai Galfarsoro, the coordinator of the acoustic and vibration group at Mondragon University: 'The reason for establishing the sound-quality project is the need to go beyond the traditional A-weighted sound pressure level, which is usually used to rank different noise sources, because we believe that a complete sound-quality analysis gives wider and more reliable results.

'The objective is to analyse the actual sound-quality performance of the various types of Orona lifts, to correlate the sound quality with the different noise sources and to study the most suitable approaches to improve the comfort of the lifts,' he added. Before carrying out the sound-quality process, the types of lifts to be analysed were selected and six of each type were tested. Three up and three down full travelling cycles (doors closing, acceleration, constant speed, deceleration and doors opening) were measured from the bottom to the top floor and back and the time data was the basis for the following sound-quality analysis.

The equipment used consisted of Bruel and Kjaer's Sound Quality Head and Torso Simulator (HATS) Type 4100-D, equipped with two microphones for binaural noise measurements. The two signals were recorded using a Pulse IDAe front-end and time data recorder software. 'The Pulse front-end is useful for measurements inside a moving lift as it makes no noise at all (its fan can be switched off during measurements) and it can be battery operated. 'Besides, time data recorder software is extremely simple to configure and use for time data measurements,' added Galfarsoro.