Measuring the Color of Clear Liquids

Liquid Fragrance Sample

Liquid Fragrance Sample

One application that often comes up is measuring the color of clean liquids such as the fragrance sample seen above. This liquid fragrances is clear and looks almost like water. Fragrances such as this are often added to cleaning supplies, air fresheners, or other consumer products. One of the problems that this type of sample can experience is that the chemistry of the liquid fragrance solution can go bad and it will start to visually yellow. This is a concern of the manufacture because if the liquid fragrance yellows it cannot be added to the end product. Continue reading

Do you have a source for Transparent Liquid Haze Standards?

HunterLab Distributor FAQ: “I have a new pharma customer doing color measurements.  They also want to do haze measurements and we had a discussion about haze standards.  Would our plastic haze standards be fine or is there a liquid haze standard out there?” Continue reading

What is a visual limit for Haze%?

FAQ: “What is a visual limit for Haze%? When should I be able to see a difference in a sample?”

A perfect clear of 0% would be air for transparent solids and the transmission cell of a defined path length filled with DI water for transparent liquids.

It should also be noted that the Haze% measurement of scatter in a sample is dependent on the thickness of transparent solid samples or cell path length of liquid samples.

The answer as to when you can see a visual difference will depend on the nature of the sample. For the plastic or glass sheets used in computer tablet screens, acceptable limits for what is faintly visible fall in the 1-2% range.

For pharmaceutical or chemical liquids, the average person may be able to see a visual difference in transmission haze at around 4 – 5%, and should definitely see a difference at a level of 6 – 7%.

To determine this for you sample, you should take a range of products exhibiting haze and get the consensus opinion of a number of people as to which samples show less than and more than visible sample. Measure Haze% using a sphere instrument and assign a visible limit specific to your product.

For many applications, especially those related to consumer products, a visible limit for haze is also the tolerance for acceptable product but not always…

Depending on the end use of the product, what is an acceptable may be below a visible limit if you don’t customer to see any visible haze difference in your product.

Or, if haze is inherent in the product and whatever is causing the product haze does not impact its use, an acceptable tolerance may be several times a visible difference. On these types of products, a typical range for good product might be from 10 to 12%, with an upper limit set at 20% just to ensure that any abnormal product is detected.

Air for transparent solids, or the cell filled with DI water or clear solvent for transparent liquids, is a physical product reference representing no haze, and the best your sample can be. A visible limit in product samples will typically be in the 2% to 5% range. What is acceptable in the marketplace will vary from less than a visible limit to some upper maximum.

What are the Flow Cell Options for Transparent Liquids?

Flow Cell Diagram combo

HunterLab D04-1015-423 flow cell with 7 mm ID/9 mm OD inlet ports, centered in D02-1009-960 Flow Through Cell Holder

A flow through cell can be a handy solution for continuous sampling and ease of measurement with a transparent, liquid product. Continue reading

Source for ASTM D1003 Transparent Plastic Haze Standards from HunterLab

You can order single Haze standards or the full set of 5 haze standards through HunterLab for use with any of our sphere instruments – ColorQuest XE, UltraScan PRO and UltraScan VIS. These solid, transparent plastic plaques (calibrated or uncalibrated) can be effective in monitoring instrument performance in measuring wide angle scattering over time.   Continue reading

How do I use the round Small Volume (4 ml) 10 mm Transmittance Cell?

HunterLab’s round cell (A13-1011-613) is a practical small volume cell for transmittance color and haze measurements. Continue reading