Measuring Carpet Using the LabScan XE
Lot-to-lot or piece-to-piece color consistency is an important indicator of quality for many colored items. Carpet can be easily measured at the sample port of a benchtop 45/0 or 0/45 instrument such as the LabScan XE.
A HunterLab LabScan XE 0/45 spectrophotometer can be used to measure the reflectance of carpet samples that are placed over the sample port. This method is recommended by HunterLab for the measurement of carpet.
The LabScan XE
The Application
Carpet samples may have several non-uniform characteristics that require compensating preparation and presentation techniques in order to ensure a repeatable sample measurement.
Carpet may not be completely opaque and may look different when backed with differently colored samples. Using a constant sample backing will minimize these effects.
The samples may be directional and/or non-homogenous, requiring the averaging of several readings with rotation.
Carpet samples are flexible, and care must be taken that they do not pillow into the measurement port.
The samples (particularly white ones) may be fluorescent, which means that they will be sensitive to the UV content of the light source.
| Recommended Color Scale | CIE L*a*b* as a full color descriptor |
| Recommended Illuminant/Observer | D65/10°. |
Measurement Method
| 1. Configure your software to read using the desired color scale, illuminant, and observer. | |
| 2. Standardize the instrument for the 1.75-inch (largest) area of view using the port insert with glass (HunterLab Part Number A02-1010-320). First standardize on the black glass, then the white tile. The instrument should be standardized in the port-up orientation. |  |
| 3. Cut a piece of carpet from the roll that is large enough to completely cover the opening in the port insert. |  |
| 4. Center the sample to be measured over the sample port and hold it in place and back it using an uncalibrated white tile with a constant weight (such as the AATCC 5-pound stainless steel weight, www.aatcc.org, order number 8381) placed on top to crush the carpet pile flat. Make sure that the area of the sample to be measured faces the port and completely covers the port. |   |
| 5. Take a single color reading of the sample. Rotate the sample 90°, move it so a different area (where the pile has not already been crushed) covers the sample port, and read it at least once more. Average the multiple color readings for a single color measurement representing its color. Averaging multiple readings with rotation between readings minimizes measurement variation associated with directionality and non-homogeneity. | |
| 6. Record the average color values. |