Inside electrical equipment, an overheated connection or a glowing fault can ignite the polymer around it long before any open flame exists. The glow-wire test reproduces that fault: a wire loop is heated electrically to a set temperature - the standard severities run from 550 to 960 degrees Celsius - pressed against the specimen for 30 seconds, and the ignition behaviour, flame persistence and dripping are observed. The method family is IEC 60695-2-11 for end products (GWT), IEC 60695-2-12 for materials (GWFI) and IEC 60695-2-13 for ignition temperature (GWIT).
How the Glow Wire Tester works
The glow wire is heated to the selected test temperature and brought into contact with the specimen under the force and for the duration the method sets. A sheet of tissue paper below catches any drips. After the wire is withdrawn, the observer records whether the specimen ignited, how long flames persisted, and whether drips ignited the tissue - the observations from which GWFI, GWIT and end-product pass/fail decisions are taken.
Key specifications
| Standards | IEC 60695-2-11 (end products), IEC 60695-2-12 (GWFI, materials), IEC 60695-2-13 (GWIT, materials) |
|---|---|
| Test temperatures | Standard severities from 550 to 960 °C, as defined in the IEC 60695-2 series |
| Application | Heated element applied to the specimen for the duration the method specifies (30 s) |
| Observations | Ignition, flame duration after removal, dripping and tissue ignition |
What the test reports
- Glow-wire flammability index (GWFI) or ignition temperature (GWIT) for materials
- Pass/fail observations for end products under IEC 60695-2-11
Applications
Appliance, component and materials laboratories run glow-wire testing for IEC 60335-family product approvals and for material selection, because many end-product standards call up a GWFI or GWIT value directly. It belongs to the same IEC 60695 fire hazard family as the needle flame test on this site.
Frequently asked questions
Which standard should I order against?
Order against the standard your reports must cite. The instrument platform is shared across the listed standards, but fixtures, software templates and calibration routines differ, so name the standard (and its year) in your inquiry and the configuration will be matched to it.
GWFI, GWIT or end-product GWT - which do I need?
Material datasheets quote GWFI (60695-2-12) and GWIT (60695-2-13); finished-product standards usually call the end-product test of 60695-2-11 at a stated temperature. Tell us which document your report must satisfy and we will configure the apparatus and accessories for it.
What temperature should I test at?
The temperature is set by your product standard, not by preference - common severities are 650, 750, 850 and 960 °C depending on the part and its position in the equipment. Check the end-product standard first, then order the configuration.
Configuration, installation and support
Every Glow Wire Tester is supplied as a configured system, not a bare instrument: the test chamber or frame, the burner or heater assemblies named in the method, the measurement chain and the control software with the report templates for IEC 60695-2-11, IEC 60695-2-12, IEC 60695-2-13. Before quotation we confirm the installation conditions with you - floor loading and ceiling height for large rigs, exhaust and extraction routes, gas and fuel services, and power supply - because a fire test instrument only produces defensible data when the room around it is right. Commissioning covers assembly, calibration of the measurement chain against the method's own checks, and training of your operators on running the test and maintaining the apparatus. Spare ignition parts, thermocouples and other consumables for the first period of operation can be included in the supply, and the instrument is supported with calibration and maintenance services after installation.
What to include in your inquiry
To quote the Glow Wire Tester correctly the first time, send: the standard and edition you will test to (IEC 60695-2-11, IEC 60695-2-12, IEC 60695-2-13); the materials or products you will test and their sizes; the configuration options you already know you need; and the destination laboratory's location and available services. If you are building a new fire laboratory rather than adding one instrument, say so - this apparatus is often planned together with the other instruments in its category, and a combined layout and exhaust plan is cheaper than three separate ones.