Case Background

The application of ultrasonic transmission techniques to geological materials, such as rocks and minerals, has advanced to the precise definition of their mechanical properties. Technicians can use such technology to quantify physical parameters of geological materials,including hardness, modulus of elasticity and grain structure,etc. It will be better to use low frequency probes because of their greater penetration and the ability to manipulate prepared samples on two parallel and flat surfaces.

Ultrasonic thickness measurement technology can not only assess the thickness of these materials without any destruction, but also detection of internal structure.Geologists can get more accurate values to analyze the physical properties and stabilities of materials. Using ultrasonic thickness measurement technology will help geologists providing powerful technical support for the prediction and prevention of geologic disasters, exploration and development of mineral resources.

Instrument and Accessory

In this case, we used PM5 Gen2 high precision ultrasonic thickness gauge to measure the marble rock. This thickness gauge can achieve accurate measurements using single-element probes, including delay line probe, contact probe, protective membrane probe,etc. Here, we selected 0.5MHz Contact Probe.This is because low-frequency ultrasound can penetrate thicker rock layers more effectively and reduce waveform distortion caused by internal structure of the rock, which can greatly ensure the accuracy and stability of the measurement results.  Clear bottom echo is essential for calculating accurate thickness values.

Measuring Procedure

Sample rocks to be measured can come in a variety of shapes and sizes, as long as they have two flat and parallel surfaces for easy coupling of the probe.First, we have to calibrate the probe. And we put the marble rock on the table, coupled the contact probe with the marble rock. The measurement mode is P-E(Pulse-Echo),because the marble has only one bottom echo. We can see the thickness value is 25.00mm.

We can see the waveform and thickness value showed as pictures. PM5 Gen2 can not only display A scan interface but also can adjust the parament related the waveform. Users can set the proper parament to get the accurate waveform.In the first picture, PM5 Gen2 shows the thickness value of marble is 10.12mm, which is wrong because the "BLANK" and "RANGE" were incorrect. After adjustment, we finally captured the correct waveform and thickness value.

If you have no idea about the marble sample's thickness and have no way to identify, you can choose the marble's velocity in the "Material Velocity List",which is equipped with standard PM5 Gen2. There are 52 kinds of material sound velocities in the list.

If you would like to learn more about PM5 Gen2 measuring case and functions, or if you are experiencing difficulties with your industry measurements, please feel free to contact us or send a sample for testing and we will provide you with the best solution!