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ISO 28927-3:2009 — Hand-held portable tools — Vibration test for polishers and sanders
Laboratory measurement of hand-transmitted vibration for surface-finishing power tools | Engineering guide
Introduction to ISO 28927-3
ISO 28927-3:2009 specifies a laboratory method for measuring hand-transmitted vibration emission at the handles of hand-held power-driven polishers and rotary, orbital and random orbital sanders used for surface-finishing processes. This standard replaces ISO 8662-8:1997 with key improvements including three-axis vibration measurement, new transducer positions, and improved definitions of transducer orientation.
This standard applies to machines driven pneumatically, hydraulically, or electrically. It does NOT apply to straight grinders equipped with a sanding wheel or to belt sanders.
Key Technical Requirements
Test Methodology and Workpiece
The standard uses a real working process: sanding or polishing is performed on a horizontal mild steel plate (E235 per ISO 630, minimum 400 mm x 300 mm x 20 mm). The machine is moved in a figure-of-eight pattern, with each pattern taking approximately 4 seconds. The total test time must allow for at least 16 seconds of integration time after stable operation is achieved.
| Machine Mass | Feed Force (additional) | Pad Type | Integration Time |
|---|---|---|---|
| < 1.5 kg | 30 ± 5 N | Manufacturer-recommended | ≥ 16 s |
| ≥ 1.5 kg | 50 ± 5 N | Manufacturer-recommended | ≥ 16 s |
Orbital and random orbital sanders are sensitive to changes in sanding pad weight because the mass is counterbalanced by internal weights. Using the wrong pad weight can significantly alter vibration readings!
Engineering Design Insights
A key innovation in this standard is the use of a real sanding task rather than a simulated load. The feed force is measured with the operator standing on a scale, providing real-time feedback to maintain consistent force application. The figure-of-eight motion pattern (approximately 50 mm radius) ensures uniform pad wear and representative vibration across the work surface.
The steel workpiece surface must have a finish Ra ≤ 8.0 µm for orbital and random orbital sanders. This surface finish is naturally achieved during preliminary testing and maintained by the test procedure itself.
For machines with two handles, the feed force must be applied on the handles perpendicular to the working surface and parallel to the pad rotation axis. This ensures the force distribution matches real working conditions.
Vibration Value Declaration
Three operators each perform five test runs. The declared vibration value ahd is the highest mean value across both hand positions. For machines with anti-vibration features, the same measurement principles apply with prescribed transducer positions on the handles.
Frequently Asked Questions
Q: What abrasive grain size should be used for testing?
A: Grain size 180 is specified for orbital and random orbital sanders. For machines not typically using grain 180, the most common grain size for that machine type should be used.
A: Grain size 180 is specified for orbital and random orbital sanders. For machines not typically using grain 180, the most common grain size for that machine type should be used.
Q: How does pad condition affect measurements?
A: Worn backing pads or bent spindles can significantly increase vibration. The abrasive paper should be worn in for approximately 1 minute before measurements and replaced when signs of wear appear.
A: Worn backing pads or bent spindles can significantly increase vibration. The abrasive paper should be worn in for approximately 1 minute before measurements and replaced when signs of wear appear.
Q: Is this standard applicable to belt sanders?
A: No, belt sanders are explicitly excluded from ISO 28927-3. They may be covered by other parts of the ISO 28927 series or separate standards.
A: No, belt sanders are explicitly excluded from ISO 28927-3. They may be covered by other parts of the ISO 28927 series or separate standards.
