Coating Thickness Standards

Certified Coated Metal Plates & Certified Polystyrene Blocks

Certified coated metal plates and polystyrene blocks are ideal for verifying the accuracy and operation of coating thickness gages and are an important component in fulfilling both ISO and in-house quality control requirements.

Many organizations require verification of gage accuracy at the test site each time a coating thickness gage is put into service and at frequent intervals during use. Ideal for this purpose, DeFelsko certified coating thickness standards have measured values traceable to a National Metrology Institution.

  • Used to verify the accuracy and operation of any Type 1 (mechanical) and Type 2 (electronic) magnetic, eddy-current or ultrasonic coating thickness gage
  • Ideal for use in the calibration lab, in the field or on the factory floor
  • Standards with steel or aluminum substrates consist of 4 plates mounted in a protective binder
  • Polystyrene thickness standards consist of 4 blocks supplied in a rugged acrylic storage box
  • Individually serialized for traceability to NIST or PTB – includes a Certificate of Calibration
  • Certified and labeled in both Metric and Imperial units
Zero Plates available for both Certified Coated Metal Plates and Certified Polystyrene Blocks.
Certified Coated Metal Plates & Polystyrene Blocks

Specifications & Ordering Guide

Certified Coated Metal Plates

Select the Standard that most closely matches the measuring range of your gage.

Certified Coated Metal Plates order code guide

All certified standards are supplied with a Certificate of Calibration traceable to NIST or PTB.
Plate Diameter: 38 mm (1.5″) Measurement Diameter: 25 mm (1″)

Certified Polystyrene Blocks

Select the Standard that most closely matches the measuring range of your gage.

Certified Polystyrene Block order guide

All certified standards are supplied with a Certificate of Calibration traceable to NIST or PTB.
P1-P7 Blocks: 38 x 70 mm (1.5″ x 2.75″)   P8 Blocks: 76 x 76 mm (3.0″ x 3.0″)

Plastic Shims

Certified Plastic Shims (foils) provide an economical alternative to coated metal plates. They have a reduced accuracy of ±2 µm (±0.08 mil). A coating thickness gage measures shim thickness when this shim is placed over a smooth metal surface (zero plate).

Non-Certified Plastic Shims (foils) provide a quick operational check of the instrument and they allow the user to perform practice measurements when placed over metal.

Alternatively, they can be placed over an uncoated metal substrate. They are not suitable for use with magnetic pull-off gages.

Shims overview:

  • Simulate a coating over a particular substrate material or shape. Gage performance can be conveniently verified on a regular basis as required by some international test methods
  • For use with all Type 2, electronic coating thickness gages
  • Protects the probe from damage or premature wear when placed over hot or abrasive surfaces
  • Can be placed on top of soft or tacky coating films to obtain thickness measurements without the gage probe depressing the coating film
  • Dimensions: 3 x 8 cm (1 x 3 inches)

Specifications & Ordering Guide

Certified Plastic Shims

  • Certified shims provide an economical alternative to Coated Metal Plates but have a reduced accuracy
  • Each shim is packaged in a protective sleeve
  • Certificate of Calibration showing traceability to NIST is included with each shim or set of shims
  • Certified and labeled in both Metric and Imperial units

Certified plastic shimsplastic shim in use

Certified Plastic Shims are available in the following thicknesses (all thicknesses are approximate):

Certified Plastic Shims order guide

Non-Certified Plastic Shims

  • Provide a quick operational check of the instrument by allowing the user to perform practice measurements
  • Can be used to protect the probe when measuring on tacky, rough or hot surfaces
  • Labeled in both Metric and Imperial units

Non-certified plastic shims

Available as a set of 5 (below):

Non-certified plastic shims order guide

Note: While DeFelsko inspects non-certified plastic shims to ensure they are within the nominal stated accuracy, they are not traceable to any national or international standard.

Zero Plate

Zero plates are uncoated steel (1018 steel) or aluminum (6061-T6) disks.  A zero plate is included with most coated metal sets. The first gage measurement is on a zero plate to verify that the gage measures zero correctly. Electronic gages can usually be adjusted to “0” if necessary. A zero plate is also a convenient base onto which a plastic shim or polystyrene block can be placed for measurement. Plate Diameter: 38 mm (1.5″)

What are zero plates used for?

  1. Coated metal Standards for magnetic and eddy current gages usually include a zero plate. The first gage measurement is on the zero plate to verify that the gage measures zero correctly. If not, electronic gages can usually be adjusted to “0” on the zero plate. Alternatively, some specifications allow the measured difference from zero to be subtracted from future coating measurements.
  2. A zero plate is also a convenient base onto which a certified or non-certified plastic shim can be placed for measurement.
  3. For best accuracy it is important to ensure a coating thickness gage meaures “0” on the uncoated substrate and adjusted to “0” if necessary. This is especially true when the substrate is rough, shaped, extremely thin, or is an alloy. When an uncoated piece of the material is not available for a zero check, some procedures call for the gage to be adjusted to “0” on an uncoated zero plate. A compensation value is then subtracted from future coating measurements.
  4. Zero plates are also used to provide a substrate where none exists. Large sheets of material such as paper, plastic, fabric and rubber can be measured with a coating thickness gage by placing the material over the zero plate. This is useful when the measured item is too large to access with a micrometer or other device. The screen printing industry uses zero plates to measure the thickness of the “substrate” being printed.
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