Amplitude measurement for quality control

Measuring vibration amplitudes in development and production

There are wanted and unwanted vibrations. These are characterized by their amplitude distribution over the frequency range and form a component-specific vibroacoustic signature: In modern control and operating panels, haptic feedback is based on a specific distribution of vibration amplitude and vibration frequency; in ultrasonic welding in production lines in the packaging industry, amplitude and frequency determine the quality of the joining and ultrasonic welding process; or in loudspeakers, amplitude and sound are closely linked because they all depend on the exact vibration amplitude and propagation on a sample surface. Manufacturers of consumer goods, infotainment hardware, medical technology or precision engineering components face the same challenge: they want to measure the vibration amplitudes in the product over the entire surface of the sample, scan the vibration frequency step by step, control the desired vibration amplitudes and, on the other hand, minimize the amplitudes of unwanted vibrations in the acoustic frequency range.

Full-field, broadband scanning of vibration amplitudes using laser interferometry

Optical and areally full-field measuring laser vibrometry as non-contact measuring technology has long been established in engineering departments. A laser sensor scans the entire surface of the product without contact nor influence on its dynamic behaviour, thus mapping the amplitude distribution on an entire frequency bandwidth with the highest precision. Desired and undesired vibrations are measured and visualized directly over the entire surface - with a single vibration sensor. A quality assurance system then classifies the product based on the reliable measurement data of the amplitude distribution. This is where Polytec's single-point laser vibration sensors and Scanning Laser Vibrometers contribute to quality control, offering flexibility, ease of use and short testing times.