The Colour Standards should always be held by the edges. Avoid touching the face with fingers or placing face down on a worktop as this may leave marks or scratches on the surface.

If the standards do become soiled, they may be cleaned by breathing on the surface and wiping gently with a tissue or clean cloth. If they become badly soiled, gently wipe the glaze surface with a pad of tissue moistened with a solution of laboratory grade detergent (this is a detergent which contains no additives such as bleaching agents, thickeners or colouring agents. It should be used following the manufacturers instructions). This should be followed by wiping with a pad moistened with clean water and a final wipe dry. If this is not sufficient, use a pad of tissue lightly moistened with Propan-2-ol (Isopropyl Alcohol), and dry off.

DO NOT, under any circumstances, subject the Colour Standards to immersion in water or to running water.

At all times care should be taken not to apply undue pressure when cleaning, to avoid a polishing action.

Measurement Of The Standards

To obtain the most reproducible results, measurements should be restricted to the central region of the standards. Ideally a jig should be used to locate the standard centrally over the measuring aperture of the instrument. However, the back pattern on each standard is designed to help in locating it in the same position for each measurement. Matt standards may have a mask of thin paper, with an appropriate size hole in it, placed between the standard and the instrument to help reduce contact of the matt surface with the instrument, prolonging its service life.

As strongly coloured standards show some thermochromism, they should always be allowed to stabilize at room temperature before measurement, and care should be taken to avoid undue heating during measurement. Neutral standards do not exhibit any appreciable thermochromism.

Validity Of Calibration

While Colour Standards are durable and very stable, we recommend that calibrated standards be recalibrated after a period of no more than five years to maintain accuracy of measurement. If the standards become damaged or permanently soiled before this time, the certificated values will not be valid and recalibration or replacement with a new standard may be necessary.