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.

Tablets, capsules and caplets come in a multitude of shapes, sizes and colors. They can be opaque, translucent and transparent.  Accurate color measurement requires not only the right instrument, but the right sample holders for accurate and consistent sample presentation. HunterLab provides a wide selection of sample holders and can customize for your specific application. The preferred instrument type will largely depend on the sample type:

Opaque Samples are impenetrable by light and are best measured using a Directional 45°/0° reflectance instrument. This is the geometry that most closely matches how the human eye ‘sees’ color.

Translucent Samples 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 plaque, then transmittance is the preferred measurement method.

– If you cannot see slight details, then reflectance is preferred.

Path length is defined as the thickness of the sample from where the light enters to where it exits the sample.

Transparent Samples allow light to pass through with little or no interruption or distortion so that objects on the other side can be clearly seen. These plaques can only be measured using transmission instrumentation.

Hunterlab Solutions

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.

LabScan XE (Directional 0°/45° Geometry, Reflectance, 400-700 nm)

10% of HunterLab customers select this instrument for its large 44 mm (1.75 inches) measuring port, and for its level of sophistication, simplicity, and versatility.

UltraScan PRO (Diffuse d/8° sphere Geometry, Reflectance and Transmittance, 350-1050 nm)

30% of our customers select this high-performance instrument for its extended wavelength measurement and its ability to measure both reflected and transmitted color.

UltraScan VIS (Diffuse d/8° sphere Geometry, Reflectance and Transmittance, 360-780 nm)

30% of our customers select this instrument for its extended wavelength measurement and its ability to measure both reflected and transmitted color of samples that are transparent to opaque.

If you are unsure which instrument type is right for your samples, please call or email us for technical support and we will be happy to assist you in making the proper instrument selection.