Corrugated Board Thickness Gauge

What is the Corrugated Board Thickness Gauge?

A corrugated board thickness gauge uses a large-diameter foot and a rigid comparator plate to measure the combined thickness of fluted board under a specified low pressure. It is required for box and packaging specification testing.

Overview

Corrugated board is thicker and more compressible than paper, so the method specifies a larger measuring foot diameter, a lower contact pressure and a rigid comparator plate that spans the flutes without deforming them. Specimens must be conditioned and measured away from scores, printing and edges, because crushing during converting reduces thickness locally and is one of the faults the test is intended to detect. Instruments are usually dial or digital gauges mounted on a stand with dead-weight loading, and some models offer interchangeable feet for single-wall and double-wall board. Since flute crushing during measurement would lower the reading, the foot must be lowered gently and remain parallel to the plate.

How does it work?

Because paper is compressible, thickness depends strongly on the pressure applied, the area of the measuring foot and the dwell time. Standards therefore define the contact pressure, usually 100 kPa for paper, the foot diameter, and the time between lowering the foot and reading the value, so results from different laboratories are comparable. A dead-weight instrument applies the load through calibrated masses on a fixed-area foot and reads displacement with a dial gauge or digital sensor, while motorised instruments lower the foot at a controlled speed and hold the specified pressure for a set interval. Board and tissue thickness use larger pressures or different foot geometries, and corrugated board requires a foot large enough to bridge the flutes and a comparator plate, so the correct geometry is defined by the product standard rather than chosen freely by the laboratory.

What are the key features?

• Large-diameter measuring foot for fluted board
• Rigid comparator plate spanning the flutes
• Dead-weight loading at low contact pressure
• Dial or digital readout
• Interchangeable feet for single and double wall
• Gentle lowering mechanism to avoid crushing

What are the technical specifications?

A typical corrugated board thickness gauge configuration offers measuring foot diameter of Per ISO 3034 or TAPPI T551, contact pressure of 20 kPa typical for corrugated board, reading resolution of 0.01 mm, measuring range of 0–20 mm, comparator plate of Rigid, flat and parallel and specimen size of At least 100 × 100 mm. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Corrugated Board Thickness Gauge is used in box and carton board specification testing, detection of flute crushing after converting, incoming inspection of corrugated deliveries and comparison of single-wall and double-wall structures. Across the wider Thickness Testing class, laboratories also deploy it for thickness and apparent density of paper and board, corrugated board caliper verification and tissue and lightweight paper thickness testing.

Which standards and certifications apply?

Relevant standards and methods include ISO 534, ISO 3034, ISO 12625-3, TAPPI T411, TAPPI T551, ASTM D645 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Condition specimens to the standard atmosphere before testing, because thickness changes with moisture and the change is not fully reversible within a short time. Clean the foot and anvil, since dust or fibre on the surfaces is added to the reading, and check the foot diameter and parallelism at intervals. Lower the foot gently at the defined speed, take the reading at the specified time and lift the foot between readings, and avoid taking measurements on the same spot twice. Verify the instrument with certified shims or gauge blocks at several points in the measuring range, and keep the calibration certificate with the instrument record.

How do I select the right Corrugated Board Thickness Gauge?

Specify a corrugated board gauge when you test fluted board to ISO 3034 or TAPPI T551, and confirm that the foot diameter, plate and contact pressure match the edition you follow. Check that the lowering action is gentle, since a foot dropped onto the board crushes flutes and gives a low reading that is easily mistaken for a production fault.

How does it compare with other Thickness Testing variants?

Select the instrument from the product standard you test against. Flat paper and board are measured with a 100 kPa dead-weight or motorised instrument with a defined foot area, tissue papers require the smaller pressure and foot of their own method, and corrugated or heavy board needs a dedicated gauge with the correct foot diameter and a rigid comparator plate. Choose a motorised instrument when many readings are needed or when operator technique must be removed, and a dead-weight instrument when simplicity and direct traceability of the applied load matter. An online caliper is specified only when continuous reel or sheet thickness data must be recorded during production, since it is measured without contact pressure and therefore correlates with, rather than reproduces, laboratory values.