How to measure material thickness using the Elcometer MTG8 Ultrasonic Thickness Gauge

The Elcometer MTG range of ultrasonic material thickness gauges accurately and non-destructively measure the thickness of materials when only one side is accessible – ideal for monitoring corrosion and erosion.

Capable of measuring almost any coated or uncoated material, for a wide range of applications – including steel pipelines and storage tanks, porcelain basins, plastic piping, or rubber linings to name a few – the Elcometer MTG range is made up of four models:

The entry-level Elcometer MTG2, a pre-calibrated gauge which simply measures the thickness of uncoated steel;
the Elcometer MTG4 and MTG6, which can measure a wide range of materials even when they’re coated;
and the top-of-the-range Elcometer MTG8, which includes all the features and functionality necessary for measuring the material thickness and sound velocity of virtually any material.

Despite their differences, every model in the Elcometer MTG range has a simple, intuitive menu system in multiple languages, so they are easy-to-use without compromising on features or functionality; dust and waterproof equivalent to IP54, ideal for use in the harshest of environments; and accurate to 1% - making this range of Elcometer NDT gauges versatile and reliable.

With the ability to measure the thickness or sound velocity of most materials - such as metals, plastics, glass, epoxies, and ceramics – the Elcometer MTG range uses a dual element transducer, and a small amount of ultrasonic couplant, to measure the substrate thickness, even when it is coated with up to 2mm of paint; ideal for when you need to measure the thickness of a coated material without damaging the coating.

Dual element transducers consist of two independent crystals, separated by an acoustic barrier. The two elements are angled so that when one crystal emits an ultrasonic pulse, the energy path creates a “V” shape, hitting the back-wall of the material, and echoing back towards the other crystal, where it is detected. The gauge then uses the speed of the pulse and the time taken to travel from one crystal to another (from pulse to echo), to calculate the thickness of the material - with the acoustic barrier preventing any sound reaching the receiver directly from emitter, before the pulse has completed its path.

Sometimes the ultrasonic signal can be deflected or weakened by the substrate material or coating, so you won’t always get a reading instantly. As a result you may have to move the probe around to obtain a reading, ensuring you have an adequate amount of ultrasonic couplant on the surface wherever you’re placing the probe. What’s more, the Elcometer MTG range only allows you to save a measurement if the signal strength indicator is in the green - avoiding false or incorrect readings.

Click here to download the script in English