Frequency dependence of resolution power

Principle
The different axial resolution power of a 1 MHz, a 2 MHz and a 4 MHz ultrasonic probe is examined on two close defects. The relationship between cycle time, sound velocity, frequency, wave length, pulse length and resolution power is illustrated in this experiment.

Tasks

1. Measure the block in the three dimensions using the calliper. 
2. Record the echo of the background in these directions and calculate the sound velocity.
   
3. Measure the period of the ultrasonic wave on the different ultrasonic probes. Calculate the frequence. Based on the sound velocity, calculate the wave length. 
   
4. Measure the width of an ultrasonic alternation (half-wave). Measure the width of a wave at 50 % of the maximum elongation (maximum of the sinus curve). The result is called the pulse-width. Repeat it for the other probes.
   
5. Measure the time of flight to the holes 1 and 2 (i.e. the two small holes right next to each other) with every single probe. Take two readings, one at the beginning of the echo, and the other one at its maximum. Based on these two figures, calculate the distance between the two holes and compare the results.

Related Topics

• Ultrasonic waves
• frequency
• sound velocity
• wave length
• axial and lateral resolution
• Ultrasonic echography (A-Scan)
• Ultrasonic imaging (B-Scan)
  

Documentation language: ENG

Literature for this article als follows

back to corresponding listview