Measure film thickness using our industry-leading thickness gauge

Introducing GPA-EVO, a cutting-edge thickness laboratory sensor born from 35 years of Octagon’s expertise in manufacturing solutions for the blown film industry.


4 reasons to measure film thickness in lab

What is Offline Film Thickness Measurement?

Offline thickness measurement, also known as measuring film gauge in lab, refers to the process of determining the thickness of a film sample outside of the production line or manufacturing environment (which is called “online thickness measurement” or “inline film gauging”) .

“Offline” implies that the measurement takes place in a controlled laboratory setting, separate from the continuous production process.



With a resolution of 1 measurement per millimeter, the GPA offers valuable data regarding the thickness profile of plastic film.


Ensure precise identification of even the slightest deviations. That data can be used to precisely calibrate your whole extrusion line.

Customer Expectations

With an accurate thickness gauge, both film buyers and film producers can be sure the negotiated terms have been met.

ISO and DIN compliance

By measuring a sample of your production, find out your ISO or DIN compliance to ensure materials supplied meet those expectations.

Empower your brand to stand alongside esteemed global leaders like Hosokawa Alpine and Exxon Mobil.

Rely on our precision thickness sensors to achieve accuracy and optimize your blown film manufacturing process and quality.

Introducing the GPA Evo

Our latest solution for offline thickness measurement for plastic film.

See the GPA Evo in action

How does it work?

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Extract data with millimetric precision

With an unparalleled resolution of 1 measurement per millimeter, the GPA offers valuable data regarding the thickness profile of plastic film including:

Powerful and simple to operate

What makes it the best thickness gauge for blown film?

Two sensors

Ensure precise identification of even the slightest deviations with the use of a contactless capacitive sensor (for relative values) and a micrometer (for absolute values), operating at the same time.

Automatic calibration

The GPA Evo is an offline thickness gauge that eliminates the need for external calibration. It achieves automatic and accurate calibration during the measurement process itself.

No PC needed

The GPA Evo has an embedded touch screen panel with GPA-Win, a user-friendly software developed to simplify the operation of taking precise thickness measurements of plastic film.

6th Generation

As the 6th generation of our globally trusted product line, the GPA Evo encapsulates 35 years of experience into our best-selling and most resistant thickness gauge solution so far.

Ultra-simple to operate

By simply inputtin two parameters through the touch screen, the GPA Evo initiates the thickness measurement process automatically. No extra actions are needed from the operator.

Wide range of films

Get precise millimetric thickness measurements of a wide variety of films, including blown film, cast film, and flat film.

The complete product in every aspect

Quality in every detail


Frequent Questions

This is very fast and simple: just put a ruler or guide on the bench and cut the samples in a strip approximately 10 cm wide. Then insert the film samples into the supplied support rack with guide rollers. The width of the film sample does not have to be accurate, e. g. it can be anything between 7 cm and 10 cm, as the equipment reads in an area of only 4.5 cm. So, no time needs to be lost when preparing the samples. It’s quick and easy.

No. The equipment has two sensors, one capacitive, the other absolute. Before inserting the film sample, the absolute sensor is used to determine the zero point as a reference. After this procedure, the measurement is carried out, the capacitive sensor measuring the film sample and the absolute sensor taking reference points for automatic calibration. For laboratories that require certification for ISO standard we provide a certificate.

Yes, the GPA is flexible. In addition to the DIN and ISO standards, measurement points can be every mm or adjusted to a number of your choice. Example: If only 10 points are required, 10 points are measured.

Yes, this system is widely used to calibrate extruders. Just fix a reference point on the die and mark the bubble exactly above this point. Then measure the sample of the tubular film.
The measured thickness profile will be presented in the polar chart of the GPA-Win software where the number of the die bolts can be selected This information allows the operator to adjust the die by either tightening or unfastening the respective die bolts.

No, in addition to tubular films it also measures segmented film samples individually or joined by adhesive tape.

Yes, laminated, pigmented and film with additives, etc. As the system operates with two types of sensors it is possible to select the measurement mode. Simply disable the capacitive sensor and use only the absolute sensor making point-to-point measurements.

Yes, the software includes a Fourier
Analysis of the measured profile. The results are shown in a graph where sine waves and their importance are analysed to indicate the distribution of symmetrical thick and thin spots. Some of these correspond with symmetrical faults of the extruded film which can be corrected. The importance of the symmetrical fault is indicated by the height of the corresponding vertical bar. For example, a film sample with 8 symmetrical thick and thin spots may indicate a problem of melt distribution caused by wrong temperatures. 6 symmetrical high and low spots may indicate a bad distribution of the cooling air. Often 13 and 15 symmetrical spots occur with an additive not plastifying well. Then just change the additive and make a new measurement to see if the problem disappears.

Yes, as a PDF. You can program this report to include your own logo.

Yes, the data can be saved in CSV format (Excel) and made available in the format required.
Yes, the data can be saved in CSV format (Excel) and made available in the format required.
To make it convenient we offer video training, if you have any questions, online training via Skype may be organized.

In two ways: The first is using the equipment to check the quality of extruded film, including from machines with online thickness control. This because the GPA is much more accurate measurement device than any online measurement system.

The second is quality control of the production process. Here the data is collected from all film reels of a production order, in this way a history is generated and a pre-established quality standard is created in which the GPA Evo is used to monitor the quality of the film produced.

The measuring unit is capable of measuring lengths from 32 cm to 20 m. The length of sample may be from 52 cm to 6 m on the standard support rack. For greater lengths oversize support racks are available.
Yes, it is possible to measure segmented samples, either separately one by one or the segments joined to a tubular strip with adhesive tape.
Ready to take the leap?

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Octagon enhances blown film extrusion all over the globe.

Meet our solutions​

Brought to you by Octagon's extensive 35-year history in manufacturing solutions for the blown film industry

Discover Octagon’s extensive range of solutions and products specifically designed for blown film extrusion. Contact our sales team today to unlock new levels of productivity and maximize your efficiency.

Automatic Air Ring


Film Thickness Measurement

PMS-B | PMS-FF | Venpad

Offline Film Gauging


Film Width Control


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