BS EN IEC 62961:2018
$142.49
Insulating liquids. Test methods for the determination of interfacial tension of insulating liquids. Determination with the ring method
| Published By | Publication Date | Number of Pages |
| BSI | 2018 | 26 |
This document establishes the measurement of the interfacial tension between insulating liquid and water by means of the Du Noüy ring method close to equilibrium conditions. In order to obtain a value that provides a realistic expression of the real interfacial tension, a measurement after a surface age of approximately 180 s is recorded.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 5 | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications |
| 7 | English CONTENTS |
| 9 | FOREWORD |
| 11 | INTRODUCTION Figures Figure 1 – Typical development of interfacial tension valuesof new and service aged mineral insulating liquids |
| 12 | Figure 2 – Typical development of interfacial tension values of a new and a service aged ester insulating liquid |
| 13 | 1 Scope 2 Normative references 3 Terms and definitions 4 Principle |
| 14 | 5 Apparatus 5.1 Tensiometer |
| 15 | 5.2 Ring 5.3 Measuring vessel 6 Preparation of apparatus 6.1 Cleaning of the measuring vessel Figure 3 – Dimensions of platinum-iridium alloy ring in mm |
| 16 | 6.2 Cleaning of the ring 6.3 Water used for the test 7 Procedure 7.1 General 7.2 Calibration and taring |
| 17 | 7.3 Determination of the surface tension of water used for the test 7.4 Determination of interfacial tension between water and insulating liquid 8 Test report |
| 18 | 9 Precision 9.1 Repeatability 9.2 Reproducibility Tables Table 1 – Repeatability (r) as a % for the measurement of interfacial tension at approximately 180 s with both manual and motor driven instruments Table 2 – Reproducibility (R) as a % for the measurement of interfacial tension at approximately 180 s with both manual and motor driven instruments |
| 19 | Annex A (informative)Determination of the interfacial tension of insulation liquids by the drop volume method A.1 General A.2 Principle of the method A.2.1 Basics |
| 20 | A.2.2 Effect of adsorption (surface age) on the values obtained A.3 Apparatus A.4 Procedure A.4.1 Preparation of apparatus A.4.2 Calibration A.4.3 Preparation of the test sample |
| 21 | A.4.4 Determination A.4.5 Evaluation/expression of results A.4.6 Correlation of results obtained with drop volume method to results obtained with ring method |
| 22 | A.5 Precision A.6 Test report Table A.1 – Comparison of interfacial values by measurement at 180 s and at 300 s to 400 s between the drop volume and ring methods |
| 23 | Annex B (informative)Investigative tests for differentiating between aged insulating liquids B.1 General Table B.1 – Interfacial tension measured in constant equal time intervals |
| 24 | B.2 Application Figure B.1 – Plot of the data from Table B.1according to Kezdy-Swinbourne method Table B.2 – Comparison of interfacial tension values by measurement at 180 s with equilibrium values according to Kezdy-Swinbourne method |
| 25 | Bibliography |
