Thickness gauges for thin sheet, foil and tape are high-precision instruments designed to measure the thickness of plastic film, thin metal foil (aluminum, copper, steel foil), textile tapes, paper and laminates. The metrological demands of these materials (sub-micrometer resolution, controlled contact force to avoid deformation, contact over a sufficient area to avoid local peaks) have led to the development of dedicated instruments that differ from standard workshop thickness gauges. They are widely used in the paper, textile, plastics and thin-metals industries and in quality laboratories.
Would you like help choosing the right product ?
Configurations and principles
Thickness gauges for thin sheet come in several configurations: bench models with a circular support platen and a micrometer probe with controlled descent according to standard (ISO 4593, DIN 53105); portable pocket models with a foot and a digital probe, for rapid measurement on samples taken from production; and roller thickness gauges, for measuring without marking the product, with a spherical or flat tungsten carbide probe. The contact force is specified by the test standards (typically 0.5-1 N over a circular area of 1-10 cm², depending on the material).
Features
Measuring ranges run from 0 mm up to 2-10 mm depending on the model, with resolutions of 0.1 µm (high-end laboratory models) or 1 µm (portable field models). Typical accuracy is ±1-2 µm on the reading for laboratory models. The contact surface is of tungsten carbide or sapphire, for durability, and spherical or flat in geometry depending on the material. Digital instruments incorporate USB/Bluetooth data output, statistical functions, measurement memory and automatic calculation of the mean over multiple samples, as the standards’ procedures require.
Applications
Typical applications include checking the thickness of plastic film for packaging (PE, PP, PET, PVC, BOPP), aluminum foil for kitchen and pharmaceutical use, copper foil for printed circuits, printing and packaging paper, corrugated board, tissue, adhesive tapes, technical textiles and laminated products. Thickness is a key product characteristic, governed by specific product standards (for example EN ISO 534 for paper, ISO 4593 for plastic film, DIN 53105 for leather).
Test standards
The main standards are: ISO 4593 for plastic film (with a Ø 16 mm platen and a force of 0.5 N), EN ISO 534 for paper (Ø 16 mm platen at a pressure of 100 kPa), ISO 2589 for leather (with its own platen and test pressure), DIN 53105 for textile laminates, and ASTM D374 for film thickness. Periodic calibration of the instruments uses sets of reference shims of known thickness, certified to ISO 17025. Checking the flatness of the contact surfaces is critical, to avoid systematic errors.
Selection criteria
The choice depends on the test standard applicable to the material (which fixes the platen size and the contact force), on the measuring range, on the resolution required, on whether the instrument is portable or for bench use, on the availability of data output for integration with quality management systems, and on the need for automation in high-volume production. Motorized models with controlled approach of the probe give the best repeatability for measurements that comply with the standards.
You must be logged in to post a comment.