VARIATION IN MASS VALUES OF INDIAN PROTOTYPE KILOGRAM |
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| Goutam Mandal, Anil Kumar, Dinesh Chandra Sharma, Harish Kumar |
- Abstract:
- The National Physical Laboratory, India (NPLI) is the custodian of National Prototype of the Kilogram (NPK) No. 57, which was provided by the BIPM in 1958 after its first calibration in 1955. The NPK has been recalibrated in 1985, 1992 & 2002 so far at the BIPM.
The change in mass values are estimated 218 µg from 1955 to 1985 (7.3 µg/year), 36 µg from 1985 to 1992 (5.1 µg/year) and 24 µg from 1992 to 2002 (2.4 µg/year) between after cleaning and washing of previous calibration to before cleaning and washing of next calibration. Now, the recalibration period of NPK is maximum 10 years.
The rate of change may, in aggregate with respect to the IPK, due to loss of mass from wear during use, increase in mass from and irreversible surface contamination and possibly, additional processes that are not yet understood.
In this paper, the BIPM method, NPL, UK formula and NMIJ, Japan formula are used to evaluate the change in mass values of NPK No. 57. - Keywords:
- stability of NPK, BIPM method, NPL, UK formula and NMIJ, Japan formula
- Download:
- IMEKO-WC-2012-TC3-P38.pdf
- DOI:
- -
- Event details
- Event name:
- XX IMEKO World Congress
- Title:
Metrology for Green Growth
- Place:
- Busan, REPUBLIC of KOREA
- Time:
- 09 September 2012 - 12 September 2012