When you say thickness measurement, the common measuring equipment that comes to mind are the ruler, tape measure and meter stick. That is because the things we usually measure are just objects. However, in an industry where the thickness of coating and sheets matter, it is impossible for a ruler, tape measure or meter stick to give precise measurements. That is why there are tools and gauges that are used to give accurate coating and sheet thickness.
For coating thickness, these are hand held instruments that can give precise outputs:
1. MPOD Family. Three models for hand held thickness gauges are available, namely Isoscope, Permascope and Dualscope.
- Isoscope is for coatings that are non-conductive applied on metals that are not ferrous. They are also applied for anodic coatings on aluminum. This uses the method called eddy current.
- Permascope measures coatings that are non-conductive and also metal coatings that are non-ferrous applied on steel and iron, using magnetic induction method.
- Dualscope, not only measures coatings that are non-ferrous metal and other coatings that are non-conductive applied on iron and steel, but it can also measure non-conductive coatings applied on non-ferrous metals. Since it can determine which method is appropriate for any given material, it can perform any of the two methods of thickness measurement
2. DeFelsko PosiTector 200. This is best described as a non-destructive ultrasonic coating thickness tool for gauging coats on wood, concrete, composite materials, plastics, etc.
3. PosiPen Coating Thickness Gauge. Most of the time, there are parts of a material that cannot be reached or measured by ordinary gauges. This is where Posipen comes in. It can be placed on hot surfaces, small surfaces and in different positions and still give accurate results.
Rubber, steel and other sheet thickness can only be measured accurately by appropriate tools like:
- MaraMeter Portable Thickness Gauges. Available in different models, some of them have built-in dial indicators or dial comparators or digital indicators. While others are perfect for taking measure of hard materials such as hardboard, sheet metal, glass panes and wooden panels, and glass panes, and some are appropriate for soft materials like foil, felt, rubber, paper and cardboard. These are available at mahr.com.
- Magna Mike. This instrument can measure the thickness of the walls of sheets and plates, bottles, tubing, containers, bulbs and lamps, scientific glassware, and even thickness of glass coatings of glass-lined tanks.
The common way of measuring the thickness is along the edge. However, with ultrasonic thickness gauges, surface measurement is now possible. Meaning, any part of the entire surface of a rubber sheet can be measured without the need to contact the opposite side of the material. This is because of the ultrasound waves that pass through rubber coating and reflect from the acoustic interface of the rubber and the substrate. However, depending on the coating, the instrument may need special set ups to ensure precise measurement.
The instruments that are suitable for surface measurement are Panametrics® Series 35 ultrasonic precision thickness gauges. These pocket-sized gauges provide accurate measurements on materials of diverse shapes and designs. Thickness measurements are shown on its built-in LCD or with the live waveform in the optional A-scan mode.