Fruits that are processed into a liquid such as fruit juice may require a different measurement approach, depending on the opaqueness of the liquid. Highly opaque fruit liquids should be measured using a reflectance instrument, while translucent or transparent fruit liquids should be measured using a transmittance instrument. For more on measuring liquids, please refer to the following PDF: HunterLab Solutions Chart.
Opaque Liquids are impenetrable by light and are best measured using a reflectance spectrophotometer that uses 45/0° geometry. This is the geometry that most closely matches how the human eye sees color.
Translucent Liquids allow light to pass through, but only diffusely, so that objects on the other side cannot be clearly distinguished. Either reflective and transmittance measurement modes may work well, depending on the translucency of the sample. As a rule of thumb,
- If at the path length that your customer will view the sample, you can see slight details of your thumb or finger through the liquid, then transmittance is the preferred measurement method.
- If you cannot see slight details, then reflectance measurement using directional 45°/0° is preferred, though it is also possible to use diffuse d/8° sphere geometry.
Path length is defined as the thickness of the sample from where the light enters to where it exits the sample. A simple test to determine the translucency is to pour the liquid into a clear container that simulates the thickness that the sample will normally be viewed, and hold your thumb on the back of the container and look through the sample.
Transparent Liquids allow light to pass through with little or no interruption or distortion so that objects on the other side can be clearly seen. These liquids can only be measured using transmission instrumentation.
Most HunterLab spectrophotometers have the versatility to accommodate most applications of color measurement. However, based on 60+ years of experience and a thorough understanding of our customers? needs and product use, these particular instruments are most suited for this industry application:
If you are unsure which instrument type is right for your samples, please call or email HunterLab technical support and we will be happy to assist you in making the proper instrument selection.
AN 1002.01 Standard Observer
CIE Standard Observers and calculation of CIE X, Y, Z color values.AN 1005 HunterLab vs CIE Lab
Measuring Color using Hunter L, a, b vs CIE 1976 L*a*b*.AN 1013 Averaging
Averaging in Color Measurement.AN 1018 Hitch Stdz
Using Hitch Standardization on a Series of Color Measuring Instruments.AN 1031 Identification of Measurement Parameters
Identification of Measurement Parameters.AN 1033 Color versus Appearance
Understanding the difference between measuring color and measuring appearance.Food Industry Brochure
The trusted choice of the world's leading food processing companies.HunterLab Solution Matrix
Geometry, Measurement Modes, and Indices.MM 5019 Measuring Flat Opaque Solids with ColorQuest XE
Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.MM 5020 Measuring Translucent Semi-Solids with ColorQuest XE
Measurement method for translucent semi-solids using the ColorQuest XE, UltraScan VIS, or UltraScan PRO.MM 5044 Measuring Flat Opaque Solids with UltraScan VIS
Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.MM 5045 Measuring Translucent Semi-Solids with UltraScan VIS
Measurement method for translucent semi-solids using the ColorQuest XE, UltraScan VIS, or UltraScan PRO.MM 5069 Measuring Flat Opaque Solids with UltraScan PRO
Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.MM 5070 Measuring Translucent Semi-Solids with UltraScan PRO
Measurement method for translucent semi-solids using the ColorQuest XE, UltraScan VIS, or UltraScan PRO.