Your liquid sample type will dictate the proper measurement instrument and technique according to the HunterLab guidelines set forth below:
Opaque Liquids are impenetrable by light, and are best measured using Directional 45°/0° reflectance 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. Both 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.
Many 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 industries 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 1001.01 APHA
Measuring the Water Whiteness of Liquids Using the APHA Index.AN 1002.01 Standard Observer
CIE Standard Observers and calculation of CIE X, Y, Z color values.AN 1003.01 Small Samples
Color Measurement on Very Small SamplesAN 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 1030 Hot Liquid Samples
The transmission color measurement of the hot liquid sampleAN 1031 Identification of Measurement Parameters
Identification of Measurement Parameters.AN 1033 Color versus Appearance
Understanding the difference between measuring color and measuring appearance.HunterLab Solution Matrix
Geometry, Measurement Modes, and Indices.MM 5008 Measuring Opaque Liquids with ColorQuest XE
Measurement method for opaque liquids using the ColorQuest XE, UltraScan PRO, UltraScan VIS.MM 5033 Measuring Opaque Liquids with UltraScan VIS
Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.MM 5058 Measuring Opaque Liquids with UltraScan PRO
Measurement method for flat, opaque solids using the UltraScan PRO, UltraScan VIS, or ColorQuest XE.