IEC TR 60695-2-16:2025

Fire hazard testing - Part 2-16: Glowing/hot-wire based test methods - Summary of the round robin tests related to the use of pyrometer for glow-wire temperature measurements according to IEC 60695-2-10

IEC TR 60695-2-16:2025 specifies the results of the round robin tests related to the use of the pyrometer, for the measurement of the glow-wire temperature, according to IEC 60695-2-10.
This Technical Report summarize the objectives and the results of a pre-round robin test and two round robin tests, performed by the IEC: "Glow-wire testing: Optimization of the temperature measuring system".
The outcome of the work conducted by the IEC resulted in a proposal for a new Annex in IEC 60695-2-10, describing the minimum technical characteristics and usage conditions for the pyrometer, as an alternative temperature measurement instrument to the thermocouple.

General Information

• Status: Published
• Publication Date: 03-Sep-2025
• ICS: 13.220.40 - Ignitability and burning behaviour of materials and products
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: TC 89 - Fire hazard testing
• Current Stage: PPUB - Publication issued
• Start Date: 04-Sep-2025
• Completion Date: 12-Sep-2025

Standards Content (Sample)

IEC TR 60695-2-16 ®
Edition 1.0 2025-09
TECHNICAL
REPORT
Fire hazard testing -
Part 2-16: Glowing/hot-wire based test methods - Summary of the round robin
tests related to the use of pyrometer for glow-wire temperature measurements
according to IEC 60695-2-10
ICS 13.220.40; 29.020 ISBN 978-2-8327-0672-5

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CONTENTS
FOREWORD. 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 11
4 Pre-round robin test . 11
4.1 General . 11
4.2 Pre-round robin test objectives . 12
4.3 Pre-round robin test plan . 12
4.4 Pre-round robin test participants . 13
4.5 Pre-round robin test results . 14
4.5.1 Glow-wire pocket hole dimensions variation . 14
4.5.2 Thermal contact between thermocouple tip and pocket hole end . 27
4.6 Pre-round robin test outcome . 40
5 First round robin test . 41
5.1 General . 41
5.2 First round robin test objectives . 41
5.3 First round robin test plan . 42
5.4 First round robin test participants . 44
5.5 First round robin test results . 44
5.5.1 Verification of pyrometer measurements in comparison to thermocouple
measurements . 44
5.5.2 First round robin test X-Ray CT scan measurements results . 87
5.6 First round robin test outcome . 93
6 Second round robin test . 94
6.1 General . 94
6.2 Second round robin test objectives . 94
6.3 Second round robin test plan . 94
6.4 Second round robin test participants . 99
6.5 Second round robin test results . 99
6.5.1 General . 99
6.5.2 Verification of heating currents . 100
6.5.3 Characteristics, usage conditions of instruments . 107
6.5.4 Pyrometer calibration . 109
6.5.5 Test plans comparison of silver (Ag) melting temperature
measurements . 111
6.5.6 Comparison of temperatures measurements . 114
6.5.7 Summary of second round robin test data quality . 122
6.6 Second round robin test outcome . 123
7 Conclusion . 123
Bibliography . 124

Figure 1 – Pre-round robin test plans . 13
Figure 2 – Glow-wire and pocket hole measured areas . 15
Figure 3 – Pocket hole depth measurement points . 20
Figure 4 – Pocket hole diameter measurement points . 22
Figure 5 – Graph of pocket hole diameter measurements . 23
Figure 6 – Laboratories thermocouple airgap in glow-wire pocket hole . 26
Figure 7 – Thermocouple silver foil melting temperatures by laboratory . 28
Figure 8 – Pyrometer silver foil melting temperatures by laboratory . 29
Figure 9 – Laboratory 1 measured heating currents at target temperatures plotting . 30
Figure 10 – Laboratory 2 measured heating currents at target temperatures plotting . 31
Figure 11 – Laboratory 3 measured heating currents at target temperatures plotting . 32
Figure 12 – Laboratory 4 measured heating currents at target temperatures plotting . 33
Figure 13 – Laboratory 5 measured heating currents at target temperatures plotting . 34
Figure 14 – Laboratory 6 measured heating currents at target temperatures plotting . 35
Figure 15 – Laboratory 7 measured heating currents at target temperatures plotting . 36
Figure 16 – Laboratory 8 measured heating currents at target temperatures plotting . 37
Figure 17 – Laboratory 9 measured heating currents at target temperatures plotting . 38
Figure 18 – Laboratory 10 measured heating currents at target temperatures plotting . 39
Figure 19 – First round robin test – Test plan 1. 43
Figure 20 – First round robin test – Test plan 2. 43
Figure 21 – First round robin test – Test plan 3. 44
Figure 22 – First round robin test – Laboratory 1 heating currents and pyrometer
measured temperatures plotting . 48
Figure 23 – First round robin test – Laboratory 1 heating currents and thermocouple
measured temperatures plotting . 48
Figure 24 – First round robin test – Laboratory 3 heating currents and pyrometer
measured temperatures plotting . 49
Figure 25 – First round robin test – Laboratory 3 heating currents and thermocouple
measured temperatures plotting . 50
Figure 26 – First round robin test – Laboratory 4 heating currents and pyrometer
measured temperatures plotting . 51
Figure 27 – First round robin test – Laboratory 4 heating currents and thermocouple
measured temperatures plotting . 51
Figure 28 – First round robin test – Laboratory 5 heating currents and pyrometer
measured temperatures plotting . 53
Figure 29 – First round robin test – Laboratory 5 heating currents and thermocouple
measured temperatures plotting . 53
Figure 30 – First round robin test – Laboratory 6 heating currents and pyrometer
measured temperatures plotting . 54
Figure 31 – First round robin test – Laboratory 6 heating currents and thermocouple
measured temperatures plotting . 55
Figure 32 – First round robin test – Laboratory 7 heating currents and pyrometer
measured temperatures plotting . 56
Figure 33 – First round robin test – Laboratory 7 heating currents and thermocouple
measured temperatures plotting . 56
Figure 34 – First round robin test – Laboratory 8 heating currents and pyrometer
measured temperatures plotting . 58
Figure 35 – First round robin test – Laboratory 8 heating currents and thermocouple
measured temperatures plotting . 58
Figure 36 – First round robin test – Laboratory 9 heating currents and pyrometer
measured temperatures plotting . 59
Figure 37 – First round robin test – Laboratory 9 heating currents and thermocouple
measured temperatures plotting . 60
Figure 38 – First round robin test – Laboratory 10 heating currents and pyrometer
measured temperatures plotting . 61
Figure 39 – Figure 38 – First round robin test – Laboratory 10 heating currents and
thermocouple measured temperatures plotting . 61
Figure 40 – First round robin test – Laboratory 1 Measured silver (Ag) melting
temperatures . 64
Figure 41 – First round robin test – Laboratory 3 Measured silver (Ag) melting
temperatures . 65
Figure 42 – First round robin test – Laboratory 4 Measured silver (Ag) melting
temperatures . 66
Figure 43 – First round robin test – Laboratory 5 Measured silver (Ag) melting
temperatures . 68
Figure 44 – First round robin test – Laboratory 6 Measured silver (Ag) melting
temperatures .
...