Product-qualification testing under ANSI/ESD STM97.2-2016 uses flooring samples mounted on support material and fitted with ground connections that simulate their intended installation. Preparation differs for floor materials, mats and topical floor finishes. The standard also specifies sample sizes and electrical properties for the supporting surface.
The standard refers to these prepared flooring samples as specimens.
Sample size and backing
Preferred and permitted sample sizes
The preferred sample size is 91 cm × 91 cm (36 inches × 36 inches). A larger sample measuring 122 cm × 122 cm (48 inches × 48 inches) may also be used (section 5.2.1.1).
For the larger sample, the nominal 6.3 mm (0.25 inch) hardboard may need another nominal 6.3 mm (0.25 inch) sheet of plywood or hardboard behind it for strength.
Mounting the flooring sample
Floor materials and mats
Mount the floor material or mat on nominal 6.3 mm (0.25 inch) tempered or standard hardboard, following the manufacturer’s recommended mounting procedures.
The hardboard must extend beyond the flooring sample in all directions. The standard’s printed metric and inch values for that extension are inconsistent, as shown in the table below.
Topical floor finishes
For a topical floor finish, use the floor surface to which the finish would be applied. Mount that surface on nominal 6.3 mm (0.25 inch) hardboard before applying the finish, then coat it according to the manufacturer’s specification.
Use conductive adhesive to fasten metallic foil in contact with the floor-finish surface as a groundable point. The standard’s printed metric and inch values for the minimum foil size are also inconsistent.
Ground connections and the support surface
Two ground connections
Each flooring sample must have two ground connections that simulate end-use grounding methods. Unless the manufacturer’s installation instructions require otherwise, a ground connection must not extend more than 7.5 cm (3 inches) into the sample (section 5.2.1.3).
Preparing two connections is distinct from connecting the sample during testing. The walking-test setup directs the tester to connect either groundable point A or B to ground (section 5.2.3.2).
Electrical properties of the support surface
A planar surface used to support the sample must meet either of these criteria:
- Surface resistivity greater than 1.0 × 10¹³ ohms/square when measured under ASTM D257.
- Surface resistance greater than 1.0 × 10¹² ohms when measured under ANSI/ESD STM11.11.
Two printed dimensions need clarification
Hardboard extension and grounding foil
ANSI/ESD STM97.2-2016 prints conflicting metric and inch dimensions for the hardboard extension and the floor-finish grounding foil. The pairs below should not be treated as equivalent conversions.
| Dimension | Metric value as printed | Inch value as printed | Inconsistency |
|---|---|---|---|
| Hardboard extension beyond the flooring sample, in all directions | 1 cm | 0.5 inch | The two values are not equivalent. |
| Minimum foil size for the floor-finish groundable point | 5 mm × 15 mm × 0.25 mm | 2 inches × 6 inches × 0.01 inch | The printed length and width pairs are not equivalent. |
This page does not select a governing hardboard extension or corrected foil size.
Before preparing the sample
Confirm the mounting procedure with the manufacturer and resolve the conflicting printed dimensions with the laboratory responsible for testing. Document the dimensions selected and the basis for that decision.
Frequently Asked Questions
ANSI/ESD STM97.2-2016 gives 91 cm × 91 cm (36 inches × 36 inches) as the preferred size and permits 122 cm × 122 cm (48 inches × 48 inches). The larger sample may need an additional nominal 6.3 mm (0.25 inch) plywood or hardboard backing for strength.
No. ANSI/ESD STM97.2-2016 requires the sample to have two ground connections that simulate end-use grounding. The walking-test setup then directs the tester to connect either point A or point B to ground.
ANSI/ESD STM97.2-2016 prints both values, but they are not equivalent. This page does not select one as governing. Resolve the discrepancy with the laboratory responsible for testing before preparing the sample.
No. For the floor-finish groundable-point foil, ANSI/ESD STM97.2-2016 prints 5 mm × 15 mm × 0.25 mm and 2 inches × 6 inches × 0.01 inch. The length and width pairs disagree. This page does not establish a corrected foil size.