Filmetrics F20s are general-purpose film thickness measurement instruments, and are used in thousands of applications worldwide.  Thickness and refractive index can be measured in less than a second. Like all of our thickness measurement instruments, the F20 connects to the USB port of your Windows™ computer and sets up in minutes.  The different F20 instruments are distinguished primarily by wavelength range. The standard F20 is Filmetrics most popular product.  Generally shorter wavelengths (e.g. F20-UV) are required for thinner films, while longer wavelengths allow measurement of thicker, rougher, and more opaque films.