The increasing use of sensors is currently revolutionizing the construction industry. Laser Doppler vibrometers have become smaller, lighter and more powerful than ever before. They are perfectly suited for mobile and in-field use. Examples are measurements of pipelines and line vibrations in industrial plants, vibrations of railroads for identification of material failure, measurements on bridges that are subject to excitation by traffic, and vibrations of buildings. They are also suitable for vibration measurements in the lab on scale-models of structures.