Ultrasonic measurement

The UAS system

The ultrasonic distance measuring system UAS facilitates non contact distance measuring in gaseous mediums on resounding surfaces, such as metal, glass, wood, liquids, and many types of fabrics. Whereby measuring accuracy amounts to +/- 100mm!

Ultrasonic distance measuring is car­ried out according to the impulse echo method, by which the distance to the test object is calculated on the basis of the running time of an acoustic impulse from the sensor to the reflecting object and back. A pulse generator produces a short transient, which effects mechanical oscillations of the elastic electrode of a sensor, and thus transmits a directed and bunched sound wave into the adjacent medium. That part of the sound wave, which has been reflected from the test object and arrived back at the sensor, is again converted into an electric impulse and amplified. By means of a clock generator, the sound's running time from transmission to reception of the reflected impulse is separated into paces of 0,05mm air gap. The single paces are counted , evaluated, stored and transmitted to the data interface for further processing.The meter reading stored during a measuring period indicates the distance between sensor and test object with a definition of max. 0,05mm air gap.

The measuring range starts from the sensor's front rim +30mm up to approx. 2mtr for passive sensors without auxiliary reflector. For sensors with auxiliary reflector, the measuring range starts approx. 30mm behind the auxiliary reflector in the sound's direction. Sensors with auxiliary reflectors are always used in cases, where highly accurate measurings are required. For measurements allowing for an accuracy of >= 3mm, or for relative measurements, no auxiliary reflector is required.

Measuring accuracy solely depends on the sensors employed, and on environmental conditions. The ultrasonic measuring system UAS always operates with a default definition of 0,01mm. This is determined by the hardware employed, and by the pulse sequence. All calculations are performed with 32 bit floating point arithmetic.

This innovative ultrasonic measuring device has the following remarkable features:

  • High measurement frequency of up to 200Hz by using a micro controller
  • RS232-interface and analogue current- and voltage exit
  • measurement value display on 5-digit LC-display
  • running time dependent amplifying adjustment of ultrasonic sound
  • reset of latest measurement value for relative measurements
  • all system parameters adjustable via interface
  • tolerance contacts

The UAS system has been designed for fitting different ultrasonic converters:

  • Sell radiator for highly accurate measurements, ± 0.1mm on short range
  • piezoceramic sound converter for measuring longer distances (up to 10mtr)


  • power unit 220VAC/24VDC