International Comparison

International Comparison

The Mutual Recognition Arrangement of International Committee for Weights and Measures (CIPM MRA) is the supporting structure through the National Metrology Institutes (NMIs) in corroborate the international equivalence of their measurement standards and the calibration and measurement certificates issued by them. The technical basis of CIPM MRA is the set of results obtained for certain range of time through scientific key comparison carried out by the Consultative Committees (CCs) of the CIPM, the International Bureau of Weights and Measures (BIPM) and the Regional Metrology Organizations (RMOs).  Essentially, there are two types of key comparisons:

  • CIPM key comparisons – The international scope that carried out by those participants that having the highest level of skills in related measurement. This type of comparisons are restricted to laboratories of Member States. From CIPM key comparisons, the reference value will be delivered for the chosen key quantity.
  • RMO key comparisons – The regional scope (SIM, AFRIMET, EURAMET, APMP, COOMETS, GULFMETS) organized at the scale of a region (may include the additional participants from other regions) and open to the laboratories of associates as well as Member States. From these key comparisons, the complementary information will be delivered without any change in the reference value.


The CIPM relegates the task of organizing the comparisons to Consultative Committees (CCs). Each CC chooses the key quantities to be compared in its field of expertise, approve the protocols of the key comparisons, and approves their results before getting published in the key comparison database (KCDB).

The RMOs organize related RMO key comparisons with a number of common participants and with protocols allowing their results to be linked to those of the CC key comparison once these are treated in terms of equivalence. The nomenclature used in KCDB reflects this organization; for instance CCAUV.A-K1 is the CC comparison to which the regional equivalents APMP.AUV.A-K1, EURAMET.AUV.A-K1, etc are linked.

CC and RMO key comparisons are carried out over specific given period of time. The result then analysed and published. The procedure may be repeated, in part or in full according to need. However, different organizational scheme is required the unique international facilities that kept in BIPM, Paris. For these, comparisons are organized as ongoing the series of bilateral comparisons between the BIPM and outside laboratories, and continue as long as there is a need.

The results for both of the international comparisons will be published by the BIPM and maintained in the CIPM MRA database (the KCDB).  As dedicated metrology institute, NMIM has participated in RMO key comparisons since 1996 started with vibration acceleration. Calibration and Measurement Capabilities (CMCs) declared by NMIM were respectively added on 4th October 2001 (date of MRA signature by Malaysia).

No. Project No. Metrology Area Measurand and parameter

Year of measurement/




Electrochemistry Comparison on pH measurement (phthalate buffer) 2015
2 APLAC T095 Inorganic Determination of elements (calcium and cadmium) in drinking water 2015
3 APMP.QM-K111 Gas analysis

Propane in nitrogen

2014 - 2015

Thermometry, Humidity

Comparison of high dew point temperature 2014


Organic Data acquisition and process in qNMR method 2014
6 APMP.T-S12 Thermometry, Pyrometry

Local realization of radiation thermometer scale from silver point to 2800 °C

Temperature: 960 °C to 2800 °C

2013 - 2016
7 APMP.T-S11 Thermometry, Pyrometry

Local realization of radiation thermometer scale from indium point to 2000 °C.

Temperatures from 156 °C to 2000 °C, and indium, tin, zinc, aluminium, silver and copper points

2013 - 2016



Arsenic and cadmium measurement in brown rice




Pb, As and Hg measurements in cosmetic (cream)

10 APMP.QM-K19 Electrochemistry pH measurement of borate buffer, pH 9.18


11 APMP.PR-K3.a Photometry and Radiometry, Photometry Luminous intensity in cd 2012 - 2014
12 CCQM-K55.c Organic

L-Valine (Characterization of organic substances for chemical purity)

13 APMP.EM.RF-K8.CL Electricity and Magnetism, Radio frequencies

Power in 50 ohm coaxial lines

Calibration factor

Frequency: 10 MHz, 50 MHz, 1 GHz, 4 GHz, 8 GHz, 12 GHz, 15 GHz, and 18 GHz

2012 - 2013



Trace and Essential elements in Herba Ecliptae




Determination of ethanol in aqueous matrix

16 APMP PT 11-02 Organic

Pesticide residue in tea

17 APMP.QM.S5 Inorganic

Essential and Toxic Elements in Seafood

18 APMP.EM-S8 Electricity and Magnetism, DC Voltage and Current

Comparison on digital multimeter

DC voltage, current and resistance
AC voltage and current

2011 - 2013
19 APMP.EM-K5.1 Electricity and Magnetism, AC Voltage, Current, Power, and AC/DC Transfer

AC power at 50 Hz/60 Hz
Voltage: 120 V
Current: 5 A
Frequency: 53 Hz

Power factor: 1.0, 0.5 Lead, 0.5 Lag, 0.0 Lead, 0.0 Lag

2010 - 2013
20 APMP.EM-K2 Electricity and Magnetism, Resistance

Comparison of resistance standards

Resistance: 10 megaohms and 1 gigaohm

2010 - 2011
21 APMP.QM.K9 Electrochemistry

pH measurement of phosphate buffer solutions (pH ~ 6.86)

           2009 - 2010
22 APMP.EM.BIPM-K11.3 Electricity and Magnetism, DC Voltage and Current

DC voltage, Zener diode

DC voltage: 1.018 V and 10 V

2009 - 2011
23 APMP.AUV.A-S1 Acoustics, Ultrasound, and Vibration, Acoustics

Comparison of sound calibrators

Sound pressure level: 94 dB and 114 dB

Frequency: 31.5 Hz to 16000 Hz

2008 - 2010
24 APMP.L-K4 Length, Dimensional Metrology

Diameter standards

Internal diameter: 5 mm to 100 mm
External diameter: 2 mm to 100 mm

2008 - 2010
25 APMP.T-K7 Thermometry, Fixed Point Cells

Comparison of water triple point cells

Temperature: 273.16 K

2007 - 2009
26 APMP.M.P-K7.1 Mass, Pressure

Pressure measurements in oil (gauge mode)

Pressure: 10 MPa to 100 MPa

27 APMP.L-S3 Length, Dimensional Metrology

Gauge block by mechanical comparison

Central length of gauge block
Steel: 1 mm, 5 mm, 10 mm, 50 mm and 100 mm
Tungsten carbide: 1 mm, 5 mm, 10 mm, 50 mm and 100 mm

2006 - 2009
28 APMP.PR-K4 Photometry and Radiometry, Photometry

Luminous flux

2006 - 2007
29 APMP.T-S1 Thermometry, Thermocouples

Comparison using Type R thermocouples

Temperature: 0 °C to 1100 °C

2005 - 2006
30 APMP.L-K1.1

Length, Dimensional Metrology

Gauge blocks by interferometry

Central length: 0.5 mm to 100 mm

2005 - 2006
31 APMP.L-K11 Length, Laser Frequencies

Comparison of primary wavelength standards

Absolute frequency of the reference component of the recommended radiation at wavelength 633 nm for the practical realization of the definition of the metre

32 APMP.T-S3 Thermometry, Industrial thermometry" >Comparison of industrial thermometers

Temperature: -40 °C to 250 °C

33 APMP.M.M-K2 Mass, Mass Standards

Comparison of mass standards

Mass: 100 mg, 2 g, 20 g, 500 g and 10 kg

2004 - 2007
34 APMP.EM-K4.1 Electricity and Magnetism, Capacitance

Comparison of capacitors

Capacitance: 10 pF

Frequency: 1592 Hz

2004 - 2006
35 APMP.AUV.A-K1 Acoustics, Ultrasound, and Vibration

Comparison of laboratory standard microphone calibrations.

Sound pressure.

Frequency: 63 Hz to 8 kHz

2004 - 2005
36 APMP.T-K4 Thermometry, Fixed Point Cells

      Comparison of local realizations of Aluminium freezing-point temperatures

      Temperature: 660.323 °C


2003 - 2005
37 APMP.EM-S7 Electricity and Magnetism, Capacitance

Comparison of capacitors

Capacitance: 100 pF

Frequency: 1.592 kHz, 1 kHz

2003 - 2006
38 APMP.M.P-K7 Mass, Pressure

Pressure measurements in oil (gauge mode)

Pressure: 10 MPa to 100 MPa

2002 - 2004
39 APMP.L-K1 Length, Dimensional Metrology

Gauge blocks by interferometry

Central length: 0.5 mm to 100 mm

2001 - 2002
40 APMP.EM-K6.a

Electricity and Magnetism

AC Voltage, Current, Power, and AC/DC Transfer

AC/DC Transfer

Voltage: 3 V
Frequency: 1 kHz, 20 kHz, 100 kHz and 1 MHz

2000 - 2003
41 APMP.T-K3 Thermometry, Standard Platinum Resistance Thermometers

Realizations of the ITS-90 from 234.3 K to 692.7 K

Temperature: 234.3 K to 692.7 K

2000 - 2003
42 APMP.L-K2 Length, Dimensional Metrology

Long gauge blocks from 200 to 500 mm

Length: 200 mm, 250 mm and 500 mm

2000 - 2002
43 APMP.T-K6 Thermometry, Humidity

Comparison of humidity standards: dew point temperature

Temperature: -60 °C to 20 °C, with 5 °C step

1999 - 2001
44 APMP.M.M-K1 Mass, Mass Standards

Comparison of mass standards

Mass: 1 kg

1999 - 2001
45 APMP.M.P-K6 Mass, Pressure

Effective area of a piston-cylinder Unit Pressure: 20 kPa to 105 kPa

1998 - 2001
46 APMP.AUV.V-K1 Acoustics, Ultrasound, and Vibration

Vibration acceleration

Amplified charge sensitivity

Frequency: 10 Hz to 10 kHz

1996 - 1997