Speed of Spread of Flame Testing Apparatus

Speed of Spread of Flame Testing Apparatus – SPK-504

Introduction

The Flame Persistency Test performed according to NF P 92-504 is a complementary reaction‑to‑fire test used for the M classification of building and furnishing materials.

This test is applied to flexible or rigid materials of any thickness that may develop holes during the main fire reaction tests, either without ignition or with only short‑term ignition during primary tests
such as the electrical burner test (NF P 92-503) or radiation test in an epiradiator cabinet (NF P 92-501).

In such cases, the flame persistency test becomes the decisive criterion for determining the final M classification of the material.

Features

Standard burner used to apply flame impact and observe flame spread behavior.
Sample holders suitable for both hard and soft materials.

Classification Principle

If no flame persists after burner removal → classification may be M1.
If flame persists → classification becomes M2 or M3 depending on duration:
- ≤ 5 seconds → M2
- > 5 seconds → M3
If ignition or non‑dripping occurs, an additional dripping test is performed according to NF P 92‑505.