Methodology

This page documents the subject of examination, the set-up, the measurement series and the selection of the test temperature. It is written so that the examination can be retraced, verified and refuted.

Subject of examination

Under examination is the glow-wire test to EN IEC 60695-2-11 in its function as the standard route of proof under EN 60335-1, Clause 30.2. The subject is not an individual product but the architecture of the proof.

Test set-up

The set-up follows the requirements of the test standard. The temperature is measured at the wire tip and recorded over the application period. The set-up and the measuring chain are described in the consolidated report. Figure 4 shows the set-up.

Measurement series

The parameters of the measurement series are summarised in the following table. Every value carries its label.

Parameters of the measurement series at the wire tip
Parameter	Value	Label
Set value of the test temperature	550 °C	Requirement of the test standard
Observed drop, lower bound	47 K	Own measurement series
Observed drop, upper bound	63 K	Own measurement series
Set value reached again within 30 s	in no series	Own measurement series
Ignitions at 550 °C in own testing	none	Own testing work, over 100 tests

Line chart: temperature at the wire tip over 30 seconds. After first contact, the curve falls below the set value of 550 degrees Celsius and does not reach it again before the end. — Figure 1: Temperature at the wire tip over the application period

Detail chart of the temperature drop at the wire tip: a drop of 47 to 63 kelvin below the set value, depending on the measurement series, without recovery within 30 seconds. — Figure 2: Temperature drop after first contact (detail)

Selection of the test temperature

The test temperature is determined by a selection diagram within the series of standards; the preferred values are 550, 650, 750, 850 and 960 °C. Its branching terms have been assigned to the product committees for definition since 2014 and are not defined there. A realistic application regularly leads to 750 °C or 850 °C. Figure 3 shows the paths.

Diagram of the selection paths for the test temperature. Realistic paths lead to 750 or 850 degrees Celsius; the standard path ends at 550 degrees Celsius. — Figure 3: Path matrix for the selection of the test temperature

The ring of references

The appliance standard refers to the test standard for the test. The test standard refers to its users for its limits. Each party may assume that the overall question has been examined elsewhere.

To the balance of direction across all documented decision points

Disclosure and interlaboratory comparison

Raw data and test set-up are disclosed. Verification in an interlaboratory comparison is invited. Professional bodies receive the raw data, the description of the set-up and the measurement records on request via the contact page.

Sources: EN IEC 60695-2-11, Clause 1 · EN 60335-1, Clause 30.2 · adoption rules of the 60695 series · Regulation (EU) No 1025/2012, Article 11 · Directive 2014/35/EU, Articles 20 and 21 (sources evidenced in the consolidated report)