How SolveTech's Proprietary Thickness Gauging Technology Works

SolveTech's gauging systems measure thickness by capacitance: the non-conductive material under test passes through a measurement field, and the system converts the resulting electrical signal into a thickness reading. Because nothing touches the film, the measurement is non-contact, high speed, and safe for the material. This approach is built for thin plastic film and other non-conductive materials, and it is the proprietary core behind SolveTech's off-line and on-line product lines.

The basic mechanism

A capacitance gauge works on a simple physical relationship: the electrical capacitance between two plates depends on the distance between them and on whatever dielectric material sits in that gap. When a plastic film is the dielectric, its thickness changes the capacitance in a predictable way.

In practice, the sequence is:

1. The material enters the measurement field. Film or sheet passes between the gauge's sensing elements.
2. The system applies an electrical signal. The non-conductive material acts as the dielectric in the capacitor formed by the measurement head.
3. The capacitance changes with thickness. A thicker section of film produces a different reading than a thinner section.
4. The signal is converted to a thickness value. The system outputs a measurement the operator or line control can act on.

Two conditions make this work: the material must be non-conductive (so it behaves as a dielectric rather than shorting the field), and the measurement must be calibrated to the material being run.

Why non-contact matters

Contact gauges — micrometers, for example — press against the film. That introduces several problems on thin plastic:

• Material deformation. Contact pressure can compress or dimple thin film, so the reading reflects the compressed thickness, not the true one.
• Speed limits. Physical contact is slow and awkward to run continuously on a moving web.
• Contamination and wear. Contact heads pick up adhesives, coatings, or debris, and they wear against the material.

A capacitance gauge avoids all three. The material passes through without being touched, so the reading is unaffected by measurement pressure, the system can run at production speed, and there is no head-to-film wear. SolveTech describes its measurements as non-contact, precise, high speed, and safe to use.

What it measures and what it does not

The technology is aimed at non-conductive materials. SolveTech's stated application areas include:

Because the method depends on the material acting as a dielectric, conductive materials are outside its scope. If you are measuring a metallized film, a conductive coating, or a metal sheet, capacitance gauging is the wrong tool — that is a materials constraint, not a tuning problem.

Off-line vs. on-line configurations

SolveTech splits its product line along where the measurement happens:

• Off-line systems — the Precision Profiler™ is described as an off-line system with high accuracy and precision. Off-line measurement is suited to roll inspection, research and development, and sample analysis, where you want a detailed thickness profile rather than a live line signal.
• On-line systems — the BF200 Blown Film Gauging System is a non-contact, on-line system designed to measure during production. On-line gauging lets you see thickness variation as the film is made rather than after the fact.

The same underlying capacitance principle applies to both; the difference is where and when the reading is taken.

Where the "proprietary" part comes in

Capacitance itself is standard physics. What SolveTech claims as proprietary is the implementation — the measurement heads, the signal handling, and the way the system is built around specific film processes. The site frames this as "Proprietary Thickness Gauging Technology" and positions each product as a market leader in its category.

For a buyer, the practical question is not whether capacitance works in principle, but whether a given system is calibrated and configured for your material, thickness range, and line speed. That is where a sample analysis is useful: SolveTech offers a free sample analysis report, which lets you see measured results on your own material before committing to a system.

Common points of confusion

"Non-contact" does not mean "no setup." The gauge still needs to be configured for the material and thickness range you are running. A reading is only meaningful once the system is set up for that film.

Thickness vs. basis weight. These are related but not the same. SolveTech's resources include film calculators for deriving thickness from weight or roll dimensions, and a GSM calculator — useful when you have weight data and want a thickness figure, or want to cross-check a gauge reading.

Repeatability is a separate question from accuracy. A gauge can be accurate on average and still vary between repeated measurements. SolveTech addresses this directly with a resource on repeatability and reproducibility, which is the right thing to check if your process control depends on tight, consistent readings.

How to decide if it fits your application

Work through these conditions:

• Is your material non-conductive? If yes, capacitance gauging is a candidate. If it is conductive or metallized, look elsewhere.
• Do you need non-contact measurement? If contact pressure, speed, or contamination is a problem on your line, this is a strong fit.
• Off-line or on-line? Choose off-line (Profiler™) for inspection, R&D, and roll profiling; on-line (BF200) for live production monitoring.
• Can you verify on your own material? Requesting a sample analysis report is the lowest-risk way to confirm the system reads your film the way you need.

If those conditions line up, the next step is matching a specific product to your film type and process — the application pages (blown film, biax, cast, converting, nonwovens, and so on) map directly to those choices.