Laboratory Luminance Contrast Testing - As per AS1428.1 - 2009 & AS1428.4.1 - 2009
Australian Standards AS1428.1 & AS1428.4.1 require laboratory luminance contrasts testing to be carried out with a specific measuring device. To quote the Standards -
B3.2 Instrumentation "A tristimulus colorimeter, or spectrophotometer with a diffuse illumination/normal viewing (d/o) geometry, is used with CIE Standard Illuminant D65. The instrument has to be capable of measuring absolute CIE for Yxy to be calculated. The measured luminous reflectance is defined by the tristimulus value Y. The chromaticity coordinates x and y provide an indication of the colour."
All of Luminos Consulting's laboratory tests are carried out with the only compliant geometric equipment and will provide details of the equipment on all reports issued as required in the Standards. It is important to note that the is NO Spectrophotometer available that actually meets the Standards requirements.
On-site Luminance Contrast Testing - As per AS1428.1 - 2009 & AS1428.4.1 - 2009
Onsite luminance contrast testing is performed using as per the equipment stated in AS1428.1 & AS1428.4.1 a single reflex lens photometer. All testing conducted on TGSI's are done in compliance with the set out requirements of AS1428.4.1 and all other building elements as per AS1428.1.
Please note that Luminos Consulting are able to conduct the laboratory tests any location and supply luminance contrast reports 24hrs after test completion.
Both laboratory and onsite luminance contrast testing includes both dry and wet luminance contrast ratios.
What You MUST Know!!!
There are companies around that test luminance contrast ratios with equipment that DOES NOT meet the requirements of AS1428.1 & AS1428.4.1.
It is essential that whenever luminance contrast tests are performed for the purposes of building compliance that the equipment be the correct geometry as stated in the Australian Standards. All tests conducted with non-conforming equipment will not hold up in any legal case.
Luminos Consulting use compliant equipment and issue reports with all required geometry and data.
How is Luminance Contrast Calculated
There are two (2) equations that are used to calculate luminance contrast.
The first equation is the Bowman-Sapolinski equation - C = 125 (Y2 − Y1)/(Y1 + Y2 + 25) which is used for the laboratory tests and the Photometer tests conducted on TGSI's and the second is found in Appendix B5.3 of AS1428.1 - 2009.
For further information about our services please feel free to contact us. If you are able to get a products or surfaces LRV (Light Reflective Value) or a cd/m2 value please use the below links to Luminos Consulting's calculators. For example if you were trying to determine whether two (2) Dulux colours achieve the 30% contrast - use the LRV's for the colours that are found in the rear of the fan deck and enter the values into the Luminous Calculator.