PosiTector 200 Max Thick Mode - measurement of the total layer thickness
on plastics, concrete, wood etc.

Max Thick mode of the PosiTector 200 simply explained:

Measurement of total layer thickness on plastics, concrete, wood, etc.

The PosiTector 200 Coating Thickness Gauge non-destructively measures coating thickness on non-metals, including coatings on wood, concrete, plastics, composites and more, using proven ultrasonic technology. With the new Max Thick mode, the PosiTector 200 is easier than ever to use.

Measurement

The PosiTector 200 probe emits an ultrasonic pulse that penetrates the coating and from any interface with different densities, e.g. B. the substrate, is reflected / echoed. The device measures the time it takes for the sound pulse to travel from the probe to the coating/substrate interface and back. By multiplying this transit time by the speed of sound through the coating (which is similar for most polymeric coatings), the thickness of the coating(s) can be calculated.

While there is almost always a density change at the coating/substrate interface that the PosiTector 200 can detect, density changes between coating layers can also be detected. The PosiTector 200 Advanced models can often detect the interface between layers of different or identical coatings, as long as the first layer is allowed to fully cure before the subsequent layer is applied. Typically, the loudest ultrasonic echo represents the layer-substrate interface, with smaller echoes representing individual layer thicknesses.

Standard measurement mode

The standard measurement mode of the PosiTector 200 has been used successfully for decades to measure film thickness on a wide variety of coatings and substrates. The PosiTector 200 searches for the loudest ultrasonic echo within its measuring range and reports this as a path length. In multi-slice mode, the thicknesses associated with the loudest echoes (depending on the number of slices selected) are reported as individual slice thicknesses. For most measurement applications, especially when measuring smooth polymer coatings, this method provided accurate total and individual layer thickness readings without the need for any adjustments or adjustments.

Applications with surface roughness or many loud echoes near the coating surface sometimes presented a challenge for measurement with the PosiTector 200, as these conditions created loud, unwanted echoes that were often larger and louder than the desired echo from the coating-substrate interface. While increasing the Lo range of the instrument would ignore these unwanted echoes, it is time consuming and sometimes difficult to make an adjustment that ignores the unwanted surface echoes while measuring thinner areas of the deposited coating.

´Max Thick-Mode´

When increasing the Lo range requires an adjustment that is too close to the expected coating thickness, or when a user simply does not want to adjust the range, the new Max Thick Mode is optimal.

When Max Thick Mode is enabled, the PosiTector 200 looks for the deepest significant echo instead of the loudest echo. This means that any loud echoes near the surface (typically caused by surface roughness or a "noisy" coating system) are ignored. This mode is often more effective in determining the total film thickness at the substrate interface and eliminates the need to adjust the instrument's preset Lo range. Since there will inevitably be some small echoes from within the substrate, only echoes above a preset volume will be reported. On the PosiTector 200 Advanced models, this threshold can be set via the Graphic Display mode. When Max Thick mode is enabled and multiple slices are selected (PosiTector 200 Advanced only), the slice thicknesses associated with the deepest ultrasonic echoes are reported.

Note: Max Thick mode is not recommended for use with thin metal substrates or composites such as carbon fiber or fiberglass.

Tip: You can update to add this feature to a PosiTector Standard (serial numbers 795,375 ) and Advanced (serial numbers 784,000 ).

Conclusion

The PosiTector 200 Ultrasonic Coating Thickness Gauge measures coating thickness on non-metal substrates such as wood, concrete, plastic and more. For most applications, the new Max Thick mode provides the most accurate readings and eliminates the need to set the Lo range to ignore incoming surface reflections.