An ultrasonic thickness gauge is a handheld device used to measure the thickness of various materials, such as metal, plastic, and glass, by utilizing ultrasonic waves. It is commonly used in industries such as manufacturing, construction, and maintenance.
How Ultrasonic Gauges Work
Ultrasonic Gauges are used to test materials for their thickness. This is done by sending a sound wave into the material. Once the soundwave hits air, there will be an echo and the gauge can then detect the thickness of the material.
The Most Important Thing to Note
Once you know the sound velocity of a material - you can get its thickness
Once you know the thickness of a material - you can get its sound velocity
Things to Prepare Before you Start
- Ultrasonic gel- this should usually come with the gauge on purchase
- Probes and the Gauge
- A sample material that is similar to what you will measure onsite (preferably thicker than 10mm
- Manual for using your particular gauge
Ultrasonic gel is important because it removes gaps that could exist between the material and the probe.
Here are some common modes found on ultrasonic gauges
- THK - this is the thickness measuring mode
- CAL - this mode is to calibrate the gauge on its provided disc ONLY
- VEL - this is to view and adjust the sound velocity of the gauge
- THK/VEL - this is for you to get the velocity of a material
Step-by-Step Guide to Using an Ultrasonic Thickness Gauge
| Step 1 and 2 | Setting up and testing your gauge and probes |
| Step 3 | Finding out the sound velocity of your material |
| Step 4 | Measuring your material thickness |
| Step 5 | Recording Measurements |
Step 1: Tool Inspection
Before using the ultrasonic thickness gauge, ensure that it is properly calibrated and in good working condition. Check the battery level and make sure the probe is clean and free from any debris.
Insert the probe into the gauge. There are 2 holes at the top of the gauge for you to insert the wires.
Step 2: Tool Set Up (Testing the Probe)
This is done to set the gauge to make sure it is working. The Disc located on the gauge is usually 3.00mm with 5900 sound velocity.
Sound Velocity refers to how fast sound travels in a particular material
Set your machine to CAL mode:
Place the probe on the disc at the bottom of the gauge with some of the ultrasonic gel. The gel creates an air-free environment for the sound wave to pass through.
The gauge will quickly register 3.00mm (the thickness of the calibrated disc) . The Velocity is also set to 5900 (the sound velocity for steel in this particular case). After this is done, most ultrasonic gauges will return to THK mode. Do not worry, this is normal.
Note:
This step only ensures your machine and probes is in good condition.
Step 3: Finding out the Sound Velocity of Your Material
Identify the material you want to measure. Different materials have different sound velocities. Not all steel is made with the same sound velocity for example.
The most important step here is to get a sample piece of material that is at least 10mm thick.
Next , use a vernier caliper to get the measure the sample material thickness and take note of this number (for example 30.14mm).
Remember:
With the sound velocity you can get the thickness of your material
With the thickness of your material you can get the sound velocity
Since you know the thickness: you can get the sound velocity of your material!
Set your gauge to THK/VEL mode. Set the value to 30.14mm and place the probe on the material. The VEL reading should appear briefly and return to THK mode.
The VEL now represents the sound velocity of your material You can check this value by selecting the VEL mode.
Step 4: Measure your Live Material Thickness
Place the probe on the live material you want to test. The thickness should automatically be shown.
Step 5: Repeat and Record
If necessary, take multiple measurements at different locations on the material to ensure accuracy. Record the measurements and any relevant information for future reference or analysis. You can also use the memory function of the ultrasonic gauge to take multiple measurements and store them.
Other notes
If you are measuring thickness on Live surfaces of different temperature, the sound velocity will change. Please contact us if you wish to find out more.
Benefits of Using an Ultrasonic Thickness Gauge
Using an ultrasonic thickness gauge offers several advantages:
- Non-destructive testing: The gauge allows for non-destructive measurement, meaning it does not damage or alter the material being tested.
- Quick and accurate: Ultrasonic thickness gauges provide fast and precise measurements, saving time and reducing human error.
- Portability: These gauges are compact and handheld, making them easy to carry and use in various locations.
- Versatility: They can be used on a wide range of materials, including metals, plastics, ceramics, and composites.
- Cost-effective: Regular thickness measurements can help identify potential issues early on, preventing costly repairs or replacements.
Conclusion
An ultrasonic thickness gauge is a valuable tool for professionals in industries where material thickness is critical. By following the step-by-step guide and using the gauge correctly, you can ensure accurate measurements and maintain the integrity and safety of your materials and structures.
