सीएसआईआर-राष्ट्रीय भौतिक प्रयोगशाला

CSIR-National Physical Laboratory

Brief details of Recent Key-Comparisons Participated / Piloted

  • Pilot laboratory for conducting the international inter-laboratory comparison (ILC) on volume (micropipettes) and Glass Scale among the South Asian Association for Regional Cooperation (SAARC) National Metrology Institute (NMIs) under the SAARC-PTB project to strength the quality infrastructure in SAARC region. This inter-comparison is under process (2019-2022).
  • Participated in the international key comparison (APMP.M.FF-K4.2.2021) on volume (micro-pipettes) organized among Asia Pacific Metrology Program (APMP) NMIs (2021).
  • Temperature and Humidity Metrology has participated in different inter-comparisons as listed in the Table below:

S. No.

Key Comparison

Parameter & range

Remarks/ Comments


SADC-Met, 2000-02

LIGT, 0 to 50 °C

Satisfactory completed


APMP-S-T7, 2006-07

S-TC, 0 to 1100 °C



APMP-KC-3, 2000-01

Hg, TPW, Ga, Zn by SPRT

Satisfactory completed


APMP-TK-4, 2005-06

Al and Ag by SPRT

Satisfactory completed


APMP-T-Pt/Pd, 2012-13

Pt/Pd TC, Co-C point   (1324 °C)

Successfully Completed



LIGT, -40°C to 250 °C

Under process



Type-R TC upto 1600 oC

Under process



SPRT on ITS-90 fixed points, -189 oC (TP Ar) to 420 oC (FP Zn)

Under process



Relative Humidity (10 % to 95 %)

Under process

Force and Hardness Metrology Section

  • The different inter-comparisons participated in the force and hardness parameters are listed in the Table below:

 List of Inter-comparisons Participated:


Identifica-tion of inter-comparison

Participated NMIs


Date of Partici-pation

Date of Report




PTB, Germany; NPLI, India.

10-100 kN,   100-1000 kN


Sep. 2011

± 0.002%

± 0.009%



NIMT, Thailand; PTB, Germany; SCL, Hong Kong; KRISS, Korea; NPLI, India.





October 2010

May 2012

0.3 HRA

0.6 HRB

0.5 HRB



KRISS, Korea; NML-SIRIM, Malaysia; NIS Egypt; NPLI, India;   A* Star, Singapore;  SCL, Hong Kong;  VMI, Vietnam; ITRI, Taipei; NIMT, Thailand; KIM-LIPI, Indonesia; KEBS, Kenya; NIM, China;  NMIJ, Japan.



March 2011

August 2018

± 0.002%

The result of the APMP M.F.-K2 force comparison of the primary standard force machine at 50kN and 100kN are depicted in Fig.1 and Fig.2 respectively, as representative figures, to a give a feeling for the reader about the accuracy and the international standing reputation of these standards.  It also reveals the importance of such inter-comparison which in fact requires a continuous maintenance for achieving the global competence. The results of the other inter-comparison carried out in the other parameters mentioned above also look similar in terms of its closeness to the key reference value of the comparison through which the CMC are reaffirmed.

Inter-comparison data at 50 kN

Inter-comparison data at 100 kN force

  1. KRISS (Korea), 2. NML-SIRIM (Malaysia), 3. NIS (Egypt), 4. NPLI (India), 5. A* Star (Singapore), 6. SCL (Hong Kong), 7. VMI (Vietnam), 8. ITRI (Taipei), 9. NIMT(Thailand), 10. KIM-LIPI (Indonesia), 11. KEBS (Kenya), 12. NIM (China), 13. NMIJ (Japan).
  • APMP.M.P K4 key comparison in the pressure range of 1 Pa to 10 kPa and submitted the results to pilot laboratory KRISS Korea
  • APMP.M.P K15 key comparison draft-A data to NMIJ, Japan in the vacuum range of 10-4 Pa to 1Pa
  • International BIPM/CIPM Key Comparison on Total Ultrasonic Power Measurement, (key comparison CCAUV.U-K3.1) (Weblink: https://iopscience.iop.org/article/10.1088/0026-1394/53/1A/09002)
  • International APMP Key Comparison on Total Ultrasonic Power Measurement (APMP TCAUV key Comparison APMP.AUV.U-K3) (Ongoing)
  • CSIR-NPL participated in an Internal Key Comparison on vibration in frequency range of 0.1 Hz to 40 Hz with Center for Measurement Standards, ITRI, Taiwan as pilot laboratory in October, 2018. The Final report of International Key Comparison Exercise, APMP.AUV.V-K3.1 circulated amongst participants in June, 2020 has validated CSIR-NPL CMCs in range 0.1 Hz to 40 Hz published in March 2021(Final report yet to be published in BIPM website)
  • Linkage of different Key comparisons, CCM.P-K13, APMP.M.P-K13, EURAMET.M.P-K13 and EURA