FAQ on Gloss
1. How often should the instrument and standard tile be recalibrated?
2. How often should I recalibrate my instrument?
3. How do I clean my reference tile?
4. Six Different Methods to Describe Gloss.
1) How often should the instrument and standard tile be re-calibrated?
It has been seen that standard tiles kept in optimum conditions can become contaminated and change up to 2 GU in three years.
Standard tiles used in "working" conditions will require regular calibration or checking.
A period of one year between tile re-calibration should be regarded as a minimum period. If a calibration standard becomes permanently scratched or damaged at any time it will require immediate recalibration or replacement.
The international standards state that it is the tile that is calibrated and traceable not the gloss-meter, however it is recommended that the instrument be also sent to an accredited service centre to verify its operation on an annual or bi-annual basis dependent on the operating conditions.
2) How should I recalibrate my Instrument?
Gloss meters are very stable and will need infrequent calibration. To judge when a calibration is necessary simply place the gloss meter on its calibration tile and take a test reading. If the reading is less than 0.2 GU from the assigned calibration value for the tile re-calibration is not necessary.
3) How do I clean my Calibration Tile?
Rhopoint standards are made of optical glass that is polished to the required gloss level. Samples should be handled with care, avoid touching the measurement face, wear gloves if appropriate.
Before calibration the tiles should be checked to ensure that they are clean and in good condition. If necessary the tiles may be wiped with a clean soft cloth moistened with warm soapy water, and dried with a lint-free cloth.