Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D5251-05 – Standard Test Method Technical Guide
📐 Apparatus Specifications and Requirements
The Tetrapod Walker Drum Tester consists of a rigid drum and a tetrapod walker. The drum has internal dimensions of diameter 205 ± 5 mm (8.0 ± 0.2 in.) and height 190 ± 5 mm (7.6 ± 0.2 in.), with a secured lid and two springs to hold the specimen. The tetrapod is a tetrahedral metal casting with four legs, each equipped with replaceable plastic feet of specified hardness.
| 🟦 Component | 📏 Parameter | 📐 SI Value | 🎯 Imperial Value | ⚡ Tolerance |
|---|---|---|---|---|
| Drum | Diameter | 205 mm | 8.0 in. | ±5 mm (±0.2 in.) |
| Height | 190 mm | 7.6 in. | ±5 mm (±0.2 in.) | |
| Tetrapod | Mass | 1000 g | 2.25 lb | ±2.5 g (±0.21 lb) |
| Height (with feet) | 125 mm | 5 in. | ±2 mm (±0.1 in.) | |
| Foot Hardness | 75 ± 5 Type A durometer | |||
⚙️ Test Procedure and Operational Parameters
The test specimen is secured as the lining of the drum with the pile surface exposed. The tetrapod walker is placed inside, and the drum is rotated about its longitudinal axis at a speed of 5.2 ± 0.2 rad/s (50 ± 2 rpm). A preset counter stops the drum after the specified number of revolutions. This practice is applicable only for unused pile floor coverings with a thickness of 20 mm (0.8 in.) or less.
| 🟦 Parameter | 📏 Specification | ⚡ Requirement |
|---|---|---|
| Rotation Speed | 5.2 rad/s (50 rpm) | ±0.2 rad/s (±2 rpm) |
| Specimen Thickness | ≤20 mm (0.8 in.) | Must not impede tumbler operation |
| Specimen Type | Unused pile floor coverings only | |
💡 For reproducible results, condition test specimens according to Practice D 1776 before testing.
⚠️ Regularly inspect and replace tetrapod feet to maintain the required hardness of 75 ± 5 Type A durometer.
❓ Frequently Asked Questions
🔍 What is the maximum pile floor covering thickness allowed for testing?
The maximum thickness is 20 mm (0.8 in.), as thicker materials impede proper operation of the drum tumbler.
💡 Why must only unused pile floor coverings be tested?
This practice is specifically designed for unused coverings; used coverings may have pre-existing texture changes that could compromise test results.
⚡ What are the critical specifications of the Tetrapod Walker?
The tetrapod has a free-standing height of 125 ± 2 mm, a total mass of 1000 ± 2.5 g, and plastic feet with a hardness of 75 ± 5 Type A durometer.
📌 How is the test specimen prepared in the drum?
The specimen is secured as the drum lining with the pile surface exposed, held in place by two springs inside the drum.