Standards - Q & A

What are STANDARDS? Certified coating thickness STANDARDS consist of a zero (uncoated) steel or aluminum plate and two or three other coated plates mounted in a durable leatherette case. They are individually labeled and serialized. Plates measure at least 35 x 35 x 2 mm. Up to 20 mils (500 microns) they are coated with epoxy. Between 500 and 1500 microns they are coated with acrylic. Over 60 mils (1500 microns) STANDARDS take the form of Plastic Blocks measuring 38 x 70 mm. Individual steel (ferrous) or aluminum (non-ferrous) plates are also available for sale either coated or uncoated. They measure 43x43mm in size and comply with the requirements of AS3894.3-200 Coating thicknesses ranging from approximately 0.3 mils (8µm) up to 750mils (19mm). What are STANDARDS used for? Certified coating thickness STANDARDS are used to verify the calibration and operation of coating thickness gages and are an important component in fulfilling both ISO and in-house quality control requirements. All DeFelsko STANDARDS are certified to an accuracy of +0.01 mils (+0.25 microns) and are supplied with a certificate of calibration showing traceability to NIST/NPL.

Plates Plastic Blocks

What are zero plates used for?

For best accuracy, a coating thickness gage should be checked that it reads "0" on the customer's 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 a uncoated zero plate. A compensation value is then subtracted to obtain a meaningful thickness result.

 

Zero plates are also used to provide a substrate where none exists. Large sheets of material such as paper, plastic 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.

Why should I use certified coating thickness STANDARDS to verify the calibration of my gage when I have plastic shims?

Your electronic PosiTector and PosiTest gages come with NON-CERTIFIED PLASTIC SHIMS for use as a quick reference out in the field or on the floor.

 

But these shims are not ideal for verifying gage calibration for the following reasons:

How do I select the appropriate STANDARD?

Certified STANDARDS are used to verify the accuracy of a gage over its complete thickness measuring range. Select the STANDARD that best covers that range. See our Specifications Chart for assistance.

Can STANDARDS be re-certified?

Yes, but the time and cost of returning them to the Australian manufacturer for re-certification is not always cost effective. The fast, affordable alternative is to trade them in on the purchase of new ones when they become visibly scratched or worn. Trade-in reduces the price of new STANDARDS by 20%.