Ultrasonic Thickness Measurement (UTM) probes are indispensable tools across a variety of industries, offering accurate, non-destructive thickness measurements of materials. Selecting the right UTM probe tailored to your industry’s specific needs can significantly enhance your quality control, efficiency, and overall performance. This comprehensive guide will compare different types of UTM probes, helping you determine which one is best for your industry.

Understanding UTM Probes

UTM probes utilize ultrasonic waves to measure the thickness of materials. These probes emit sound waves into a material and measure the time it takes for the waves to bounce back. This data is then used to calculate the thickness of the material. UTM probes are crucial for ensuring product integrity, safety, and compliance with industry standards.

Types of UTM Probes

Different types of UTM probes are designed to cater to various applications and material types. Here, we will discuss the main types of UTM probes and their specific uses:

1. Single-Element Probes

Single-element probes, also known as contact probes, are the most common type of UTM probes. They consist of a single transducer that emits and receives ultrasonic waves.

  • Applications: Ideal for measuring metals, plastics, ceramics, and composites with smooth and relatively clean surfaces.
  • Industries: Widely used in manufacturing, automotive, aerospace, and construction.
  • Advantages: Simple to use, cost-effective, and versatile.

2. Dual-Element Probes

Dual-element probes have two transducers: one for emitting and one for receiving ultrasonic waves. This design reduces the effect of surface roughness and improves measurement accuracy on corroded or rough surfaces.

  • Applications: Suitable for measuring corroded, eroded, or coated materials.
  • Industries: Commonly used in the oil and gas, maritime, and power generation sectors.
  • Advantages: Enhanced accuracy on rough surfaces, better penetration in thicker materials.

3. Delay Line Probes

Delay line probes use a delay line (a medium between the transducer and the material) to enhance the resolution and accuracy of thickness measurements, especially on thin materials.

  • Applications: Excellent for measuring thin materials and layers.
  • Industries: Frequently used in the electronics, automotive, and aerospace industries.
  • Advantages: High resolution, precise measurements on thin materials, and effective at higher temperatures.

4. Immersion Probes

Immersion probes are designed to operate in a liquid environment, allowing for precise measurements on complex shapes and underwater structures.

  • Applications: Ideal for inspecting parts with complex geometries and underwater applications.
  • Industries: Used in the marine, aerospace, and manufacturing industries.
  • Advantages: High precision, excellent for complex shapes, and non-contact measurement.

5. High-Temperature Probes

High-temperature probes are specifically designed to withstand extreme temperatures, making them suitable for environments where standard probes would fail.

  • Applications: Used in high-temperature environments, such as furnaces and reactors.
  • Industries: Common in the power generation, metal processing, and petrochemical industries.
  • Advantages: Durable, reliable measurements in high-temperature settings.

Industry-Specific Considerations

Selecting the right UTM probe involves understanding the specific requirements and challenges of your industry. Let’s explore which UTM probes are best suited for different industries:


In manufacturing, consistency, and accuracy are paramount. UTM probes are used to ensure that products meet precise thickness specifications, which is crucial for maintaining quality and performance.

  • Recommended Probes: Single-element and dual-element probes.
  • Applications: Measuring metals, plastics, and composites.
  • Advantages: Cost-effective, versatile, and reliable for a wide range of materials.


The automotive industry requires precise thickness measurements for components such as body panels, engine parts, and brake pads. Accurate measurements ensure safety, performance, and compliance with standards.

  • Recommended Probes: Single-element, dual-element, and delay line probes.
  • Applications: Measuring metals, plastics, and coatings.
  • Advantages: High accuracy, suitability for thin materials and coatings, and reliable performance.


Aerospace components must adhere to stringent safety and performance standards. UTM probes are used to measure the thickness of various materials, including metals and composites, ensuring structural integrity.

  • Recommended Probes: Single-element, dual-element, delay line, and immersion probes.
  • Applications: Measuring thin materials, complex shapes, and underwater structures.
  • Advantages: High precision, suitable for complex geometries, and reliable in critical applications.

Oil and Gas

The oil and gas industry deals with harsh environments, where corrosion and erosion can affect the integrity of pipelines, tanks, and other equipment. UTM probes are essential for detecting and measuring these issues.

  • Recommended Probes: Dual-element and high-temperature probes.
  • Applications: Measuring corroded and eroded surfaces, high-temperature environments.
  • Advantages: Enhanced accuracy on rough surfaces, reliable in extreme conditions.


In the maritime industry, UTM probes are used to measure the thickness of ship hulls, underwater structures, and other components exposed to harsh marine environments.

  • Recommended Probes: Dual-element, immersion, and high-temperature probes.
  • Applications: Measuring underwater structures, corroded surfaces, and high-temperature environments.
  • Advantages: High precision, effective on rough surfaces, and reliable underwater.


The electronics industry requires precise measurements of thin materials and layers. UTM probes ensure the quality and performance of electronic components, such as circuit boards and semiconductor wafers.

  • Recommended Probes: Delay line and single-element probes.
  • Applications: Measuring thin materials and layers.
  • Advantages: High resolution, precise measurements, and effective at higher temperatures.

Key Factors to Consider

When choosing the right UTM probe for your industry, consider the following factors:

1. Material Type

Different materials have unique acoustic properties that affect the choice of UTM probe. Ensure the probe you select is suitable for the materials you work with.

2. Thickness Range

Choose a probe that can accurately measure the thickness range required for your applications. High-frequency probes are better for thin materials, while lower frequency probes are suitable for thicker materials.

3. Surface Condition

Consider the surface condition of the material. Rough, corroded, or coated surfaces may require specialized probes, such as dual-element or delay line probes.

4. Temperature

Ensure the probe can withstand the temperatures of your working environment. High-temperature probes are necessary for extreme conditions.

5. Geometry and Accessibility

Consider the geometry and accessibility of the measurement area. Immersion probes are ideal for complex shapes, while miniature or angle beam probes are suitable for tight or hard-to-reach areas.

6. Frequency

The frequency of the UTM probe affects its resolution and penetration capabilities. Higher frequencies offer better resolution, while lower frequencies provide deeper penetration.


Selecting the right UTM probe for your industry is essential for ensuring accurate, reliable, and efficient thickness measurements. By understanding the specific requirements and challenges of your industry, you can choose a UTM probe that meets your needs and enhances your quality control processes.

Whether you work in manufacturing, automotive, aerospace, oil and gas, maritime, or electronics, there is a UTM probe designed to optimize your measurements and improve your operational performance. Investing in the right UTM probe not only ensures product quality and compliance with standards but also boosts productivity and reduces costs.