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Spectral Analysis: An Effective Method for Measuring Plastic Coating and Film Thickness

Posted on Jan 27, 2026 by HunterLab

Plastic films and coatings are widely used in today’s manufacturing industries. Spectral analysis addresses measurements of thickness and quality in these products. Image Source: Flickr user Dom Pates

The applications of plastic and polymer use in manufacturing are limitless, and industries are finding new ways to utilize this flexible and durable material all the time. With polymer prices on the rise, many major corporations are relying on spectral analysis to ensure effective product performance and to help reduce wasted materials.

Plastic films and coating make up a large portion of the plastic manufacturing industries and have been used to add strength and protection to a variety of products we use today. From wires and cords to windows and metal products, polymer coatings extend the durability and performance of these materials and provide a more economical and functional product. Spectrophotometers are able to measure plastic film and coating thickness using spectral analysis, providing a valuable method for improving both quality and cost efficiency.

Using Spectral Data to Measure Polymer Properties

Plastic is a highly durable, lightweight material, which makes it ideal for a number of manufacturing applications. These applications require instrumental analysis to measure the specific properties of polymers. These materials are typically transparent in quality and are measured using transmittance, reflectance, transparency, and color measurement methods of evaluation. By measuring these optical properties, calculations can be made to determine the thickness and reflection value of plastic coatings for precise visibility, functionality, and quality control.

The details of how HunterLab sphere instruments conform to ASTM D1003 Section 8: Procedure B Spectro

Posted on Jan 27, 2026 by HunterLab

HunterLab sphere instruments with CIE d/8 geometries conform to the requirements of ASTM D1003 Section 8: Procedure B Spectrophotometer. The measurement of transmission haze using Procedure B instruments will be in close agreement with ASTM D1003 Procedure A Haze meter.

Meeting ASTM D1003 Section 8 Procedure B Requirements

Here is a more detailed description of how the HunterLab UltraScan PRO and UltraScan VIS meet the requirements of Section 8.

Procedure B (Spectrophotometer)

8.1 Apparatus:

8.1.1 The instruments used for measurement shall meet the geometric and spectral requirement of this section.

HunterLab UltraScan VIS and UltraScan PRO instruments meet ASTM D1003 Section 8 Procedure B Spectrophotometer requirements.

8.1.2 The instrument shall be capable of computing from the spectral data the 1931 CIE tristimulus values and related color coordinates for CIE standard Illuminant C or alternatively Illuminant A.

HunterLab offers A/2 and C/2 options for calculating Haze%, Y Total and Y Diffuse luminous transmission in EasyMatch QC software.

8.1.3 The instrument shall utilize a hemispherical optical measuring system, with an integrating sphere, in which the specimen can be placed flush against the sphere port. The surfaces of the interior of the integrating sphere, baffles, and reflectance standards shall be matte, of substantially equal reflectance and highly reflecting throughout the visible wavelengths.

HunterLab UltraScan VIS and UltraScan PRO sensors and internal components are coated with Spectralon having a 99%+ reflectance. Transparent specimens for haze measurement are placed at the TTRAN port, flush against the sphere.

The UltraScan VIS and Pro come with white, Japanese commercial opal reflectance standard of 99%+ reflectance.

8.1.4 Two geometries can be used: unidirectional illumination with diffuse viewing and diffuse illumination with unidirectional viewing. Using diffuse illumination with unidirectional viewing, the following apply:

HunterLab UltraScan VIS and UltraScan PRO sensors have a diffuse illumination with unidirectional viewing (8°) geometry. They are referred to as CIE-conforming diffuse d/8° sphere instruments.

8.1.4.1 Use an integrating sphere to illuminate the specimen diffusely; the sphere may be of any diameter as long as the total port areas do not exceed 4.0 % of the internal reflecting area of the sphere. The specimen and light trap ports of the sphere shall be centered on the same great circle of the sphere, and there shall be at least 2.97 rad (170°) of arc between their centers.

The light trap port shall subtend an angle of 0.14 rad (8°) at the center of the specimen port along the wowing beam. With the light trap in position, without specimen the axis of the viewing beam shall pass through the centers of the specimen and light trap ports.

Using ASCII Export on Multiple Jobs

Posted on Jan 27, 2026 by HunterLab

Can you use the Automatic ASCII Export feature on more than one Job so that each Job exports to a separate file?

Providing everything is setup correctly within the EasyMatch QC software, it is possible to use the Automatic ASCII Export feature on more than one Job and to have each Job export to a different file. To make sure this is setup properly each Job must be saved once the ASCII Export configuration has been set. For more information on setting up the ASCII Export please see our blog note here.

Once you have designated the file name to be used in the ASCII Export Configuration screen make sure you go to File/Save Job. This will save your ASCII Export Configuration settings to your Job. You can then create a new Job, or open a Job and go to Options/ASCII Export/Configure and use a new file name as the designated location. When you are finished go to File/Save Job to save the configuration. This can be done for as many Job files as you need. Just be certain once you designate the export file name and location in Options/ASCII Export/Configure to save the Job by going to File/Save Job.

Using Spectrophotometry for Accurate Haze Measurement to Improve Quality Perception of Beer

Posted on Jan 27, 2026 by HunterLab

Haze can have a significant impact on consumer perception of beer quality. Image Source: stock.tookapic.com

Creating the perfect beer is truly a craft. Both beer connoisseurs and casual drinkers alike often know exactly what they’re looking for in a beer and, just as importantly, what they’re not looking for. As such, breweries must take great care in creating beers that not only taste delicious but are appealing to the eye. One of the primary aesthetic concerns breweries face is haze, or turbidity, which interferes with the clarity of beers and can drastically affect consumer purchasing decisions as well as taste and quality perception.

Seeking Clarity

Haze is the scattering of light by fine particles that produces a clouding effect in transparent liquids. In beer, haze particles are typically the result of non-biological factors such as starches, lipids, proteins, polyphenols, and colloidal carbohydrates. At times, haze from these sources may only be apparent in cold conditions, a phenomenon known as “chill haze.” In other cases, haze is caused by biological components such as microorganisms, which can indicate contamination and is a non-reversible feature of the beer. Although haze has no inherent meaning—it may be a benign aesthetic quality, a predictor of shelf life, or a major indicator of spoilage—its presence is typically undesirable for consumers regardless of whether or not it impacts taste. As Professor Chengdao Li says, “Beer drinkers are becoming more sophisticated, they want a beer looking good, very clear with good colour and no haze.”1 Driven by this market demand, researchers have spent considerable time investigating how to eliminate haze through raw ingredient selection, beer formulation, and specific processing methods designed to eliminate cloudiness. Meanwhile, both the European Brewery Convention (EBC) and the American Society of Brewing Chemists (ASBC) have developed haze measurement standards to classify brews according to clarity.2

Spectrophotometric haze measurement can be a critical part of evaluating the impact of beer variables, such as wheat variety. Image Source: Pexels user Zugr

What are Hydrochromic or Hygrochromic Color Samples?

Posted on Jan 27, 2026 by HunterLab

Both “hydro” coming from Greek origins for water and “hygro” coming from the Greek “hygrós” for wet or moist, tend to be used in two terms for the same optical phenomena.

ASTM E284 on standard appearance terminology prefers the name “hygrochromic”.

What is HCCI – HunterLab Coffee Color Index?

Posted on Jan 27, 2026 by HunterLab

HCCI – HunterLab Coffee Color Index measures the reflectance of ground coffee products at 640 nm, which is optimal for defining the degree of roast.

HCCI works best for measuring during the roasting process, taking the coffee product to a consistent end point.

HCCI = [HCCI_slope * R%(640 nm)] + HCCI_offset

where default coefficients for HCCI_slope = 1.958 and HCCI_offset = – 3.32.

HCCI* comes with a user-adjustable bias and offset in each setup to allow display in agreement with existing instruments.

HCCI values are typically displayed to 1 decimal place.

HCCI correlates well with the visual SCAA Roast Standards and exhibit 20 unit range.

The HunterLab ColorFlex EZ Coffee meter comes with a built-in correlation to report HCCI – HunterLab Coffee Color Index, SCAA # and SCAA Roast Classification, all used to quantify the degree of coffee roast.

HunterLab ColorFlex Coffee with HCCI# with correlated SCAA# and SCAA Roast Classification displayed.

What Path Length Cell should I use for APHA/Pt-Co/Hazen Color Measurement?

Posted on Jan 27, 2026 by HunterLab

FAQ: ” We are currently using a 10 mm path length and read in the 0 – 50 region for APHA/Pt-Co/Hazen Color, usually in the area of 10. Would you recommend a 10 mm path length with our equipment for this application?”

“APHA Color” is also known by two other names – “Pt-Co Color” and “Hazen units (HU)”. All three names represent the same color scale. As the APHA/Pt-Co/Hazen Color is dependent on the path length or thickness of the sample, it is important to:

Use the same cell path length for all measurements.
Report the cell path length as part of the measurement method if inter-instrument agreement of APHA/PtCo/Hazen Color values is important at multiple sites.

HunterLab’s instrument correlation to the visual APHA/Pt-Co/Hazen Color scale per ASTM D5386 allows the user to select a 10-mm, 20-mm or 50-mm path length cell by configuring the Color Data View in EasyMatch QC software to display “APHA-10mm”, “APHA-20mm” or “APHA-50mm”.

While any of these three cell path lengths can be used to effectively measure APHA/Pt-Co/Hazen Color, the optimal choice for cell path length choice is based on the following criteria:

A 10-mm path length cell is typically used for highly saturated or chromatic liquids, typically with APHA/Pt-Co/Hazen Color values > 300.
The easy-to-fill 20-mm path length cell is used for moderately chromatic liquids, and is the default cell path length when a wide APHA/Pt-Co/Hazen Color range of liquid colors is being measured from 0 (distilled water) to 500.
The longer 50-mm path length cell is preferred for clear or near clear liquids where APHA/Pt-Co/Hazen Color values < 30, and especially when APHA < 10.

Interested in a little light reading?

"Spectral Analysis: An Effective Method for Measuring Plastic Coating and Film Thickness"

"The details of how HunterLab sphere instruments conform to ASTM D1003 Section 8: Procedure B Spectro"

"Using ASCII Export on Multiple Jobs"

"Using Spectrophotometry for Accurate Haze Measurement to Improve Quality Perception of Beer"

"What are Hydrochromic or Hygrochromic Color Samples?"

"What is HCCI – HunterLab Coffee Color Index?"

"What Path Length Cell should I use for APHA/Pt-Co/Hazen Color Measurement?"

Spectral Analysis: An Effective Method for Measuring Plastic Coating and Film Thickness

Using Spectral Data to Measure Polymer Properties

The details of how HunterLab sphere instruments conform to ASTM D1003 Section 8: Procedure B Spectro

Meeting ASTM D1003 Section 8 Procedure B Requirements

Using ASCII Export on Multiple Jobs

Can you use the Automatic ASCII Export feature on more than one Job so that each Job exports to a separate file?

Using Spectrophotometry for Accurate Haze Measurement to Improve Quality Perception of Beer

Seeking Clarity

What are Hydrochromic or Hygrochromic Color Samples?

What is HCCI – HunterLab Coffee Color Index?

What Path Length Cell should I use for APHA/Pt-Co/Hazen Color Measurement?

FAQ: ” We are currently using a 10 mm path length and read in the 0 – 50 region for APHA/Pt-Co/Hazen Color, usually in the area of 10. Would you recommend a 10 mm path length with our equipment for this application?”