What is the difference between thickness and basis weight?
Thickness is the physical distance between the two surfaces of the web. Basis weight is mass per unit area. X-ray transmission fundamentally responds to attenuation through the material and is strong for mass-per-area measurement. Reporting equivalent thickness requires a qualified relationship to density and composition; direct physical thickness uses an appropriate geometric method.
Can one downstream scanner measure coating add-on?
It can when the substrate contribution is sufficiently stable, separately known, or included in a proven model. If the incoming substrate changes across the width or along the roll, one downstream total may confuse substrate variation with coating variation. Registered pre-coat and post-coat stations provide the stronger architecture in that case.
Does a Scantech scanner inspect every square millimeter?
A traversing scanner measures many positions and builds a full-width statistical profile as the web moves, but its exact coverage depends on spot size, scan speed, line speed, and sampling configuration. Use the quoted resolution and response rather than a blanket “100% inspection” claim. A separate camera or defect-inspection system may be needed for pinholes, contamination, streaks, and other visual defects.
Does an X-ray web gauge use a radioactive isotope?
Scantech uses electronically generated low-energy X-ray rather than a sealed radioactive beta isotope. The installed system still requires the manufacturer’s guarding, interlocks, safety procedures, training, and local compliance review. “No isotope source” is more accurate than calling any X-ray system radiation-free.
Does web tension affect coating quality?
It can. Unstable or uneven tension may contribute to wrinkles, lateral movement, registration errors, variable contact at rolls or nips, stretching, poor lamination, slitting problems, and bad roll formation. Tension data does not replace coating measurement, but it can explain why a good coating profile changes downstream.
What is a dead-shaft roller?
On a dead-shaft roller, the center shaft stays fixed while the outer roller shell turns on bearings. The FMS CA-Series fits compatible dead-shaft idlers. On a live-shaft roller, the shaft rotates with the roller and a different sensor family is used. Do not assume the roller type from the machine’s age or location—inspect both ends or use a drawing.
Does tension monitoring automatically control tension?
No. Monitoring measures, displays, trends, alarms, or sends tension data to the PLC. Automatic adjustment additionally requires a compatible tension controller, brake or drive hardware, machine safeguards, and a reviewed control strategy.
Why use segFORCE instead of two conventional load cells?
Two end-mounted sensors provide the total tension and may show a left-to-right imbalance. They can still hide a tight center lane or several loose slit lanes. segFORCE uses multiple independent positions to produce a tension profile across the width, which is useful when local web differences—not the total average—drive the defect.
Can measurement data automatically correct the coating profile?
Only when the line has a suitable actuator and the relationship has been proven. Depending on the process, a control may affect coating flow, pump speed, gap, line speed, nip, a compatible die zone, or another machine variable. Cross-direction and machine-direction controls are different loops. Transport delay, scan time, mapping, limits, interlocks, and fallback behavior must be defined.
What should I send for a preliminary recommendation?
Send the material and complete layer structure, target output and units, wet/dry state, web width, speed, temperature, scanner locations, current laboratory method, known defects, and desired reports or controls. For FMS, also send minimum and maximum tension, roller photographs or drawings, entry and exit angles, roller weight and diameter, shaft construction, mounting, and the brake, drive, PLC, or guiding hardware.
