Colour Measurement: two new best practice guides launched by the Society of Dyers and Colourists
The Society of Dyers and Colourists (SDC) today announced the launch of two new best practice guides, for use with instrumental and visual colour assessment. The guides have been written by SDC’s Colour Measurement Committee, which has been an integral part of SDC for many years. Both guides are being made available freely by SDC as part of their charitable remit to educate and inform about colour.
They are as follows:
- Assessment of the Performance of a Colour Measurement Instrument
- Viewing Cabinets for the Visual Assessment of Surface Colour
The best practice guides are available via SDC’s website, or on request from the Society.
So why have they been written? The guides aim to tackle a number of common issues such as:
- ensuring laboratory managers know what specification is required for the equipment for the assessment of colour to be effective
- highlighting the variables that exist and how to minimise these to ensure that the work is as effective as possible
These best practice guides provide guidance on the assessment of the performance of a colour measurement instrument and for viewing cabinets highlight the main areas that need to be considered during the purchase and use of the equipment.
Many laboratory managers assume that a colour measuring instrument will work in a consistent way over a period of many years with little or no maintenance. They also assume that each measurement is perfect and not subject to any variation measurement due to extraneous circumstances.
Assessment of the Performance of a Colour Measurement Instrument can be used to assess the performance of an instrument that is used for the measurement of surface colour. It is assumed that the instrument is a spectrophotometer and all examples given are based on such an instrument.
The guide considers the performance in terms of uncertainty of measurement. These uncertainties are themselves considered in terms of repeatability or precision, and reproducibility or accuracy. While these can be considered the main contributors to the uncertainty in any measurement, a number of other likely contributors are also described.
The other best practice guide – Viewing Cabinets for the Visual Assessment of Surface Colour provides a physical, colorimetric and photometric specification for viewing cabinets for the general visual assessment of colour surfaces or objects, including the assessment of colour appearance, colour differences, metamerism and colour constancy, using diffuse lighting.
Both guides provide the user with the information required to be able to make sure that the instrument in use is being used to its maximum efficiency and therefore providing more accurate and relevant data.
The guides link in with two other publications which are available for purchase from SDC:
- Best practice guide – colour matching assessment of textiles
- SDC Standard 1/01:2008 Visual colour of textiles – method
These publications provide a more practical approach to the actual methods of using the equipment and ensuring accurate results by employing the best procedures available. All the documents should be used together in any laboratory performing both visual and instrumental colour assessment.