The KCDB - the BIPM key comparison database – supports the CIPM MRA. The KCDB contains information on the internationally recognized Calibration and Measurement Capabilities (CMCs) for services available from the participating institutes, and the key and supplementary comparisons supporting these CMCs.

All data listed in the KCDB have been reviewed and approved within the CIPM Mutual Recognition Arrangement
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In the CMCs uncertainty statements, the notation Q[*a*, *b*] stands for the root-sum-square of the terms between brackets: Q[*a*, *b*] = [*a*^{ 2} + *b*^{ 2}]^{1/2}

*Unless otherwise stated the expanded uncertainties given below correspond to **k* = 2 (at a 95 % level of confidence)

Luxembourg, ILNAS (Bureau Luxembourgeois de Métrologie)

Time scale difference ,
Time scale difference
:
**-1 s to 1 s**

Local clocks vs UTC(LUX)

Absolute expanded uncertainty
:
**2 ns**

Time interval counter

Pulse amplitude : > 1 V on 50 Ω

Rise time : < 5 ns

Approved on 31 August 2021

Frequency ,
Frequency
:
**0.1 MHz to 4.00E4 MHz**

Frequency counter

Relative expanded uncertainty
:
**5.0E-12 Hz/Hz**

General frequency source

Averaging time : 1000 s

Approved on 31 August 2021

Time scale difference ,
Time scale difference
:
**-1 s to 1 s**

Remote clocks vs UTC(LUX)

Absolute expanded uncertainty
:
**2.0E1 ns**

GPS TAIP3 common view

Averaging time : 1 d

Approved on 31 August 2021

Time interval ,
Time interval
:
**1000 s to 1.00E5 s**

Time difference source

Absolute expanded uncertainty
:
**2.0E2 ns**

Time interval counter

Pulse amplitude : > 1 V on 50 Ω

Rise Time : < 10 ns

Approved on 31 August 2021

Frequency ,
Frequency
:
**10 kHz to 100 kHz**

Frequency counter

Relative expanded uncertainty
:
**2.0E-10 Hz/Hz**

General frequency source

Averaging time : 1000 s

Approved on 31 August 2021

Frequency ,
Frequency
:
**1 Hz to 1.00E4 Hz**

General frequency source

Relative expanded uncertainty
:
**8.0E-11 Hz/Hz to 8.0E-7 Hz/Hz**

8E-07/f with f the frequency measured

Direct frequency measurement

Averaging time : 1000 s

Amplitude : 1 to 5 V (50 ohm)

Approved on 31 August 2021

Frequency ,
Frequency
:
**0.35 GHz to 40 GHz**

General frequency source

Relative expanded uncertainty
:
**2.0E-12 Hz/Hz**

Direct frequency measurement

Averaging time : 1000 s

Amplitude : max 18 dBm (50 Ohm)

Approved on 31 August 2021

Time interval ,
Time interval
:
**1.00E-9 s to 1000 s**

Time difference source

Absolute expanded uncertainty
:
**2 ns**

Time interval counter

Pulse amplitude : > 1 V on 50 Ω

Rise Time : < 10 ns

Approved on 31 August 2021

Frequency ,
Frequency
:
**10 Hz to 1.00E4 Hz**

Frequency counter

Relative expanded uncertainty
:
**1.0E-7 Hz/Hz to 1.0E-10 Hz/Hz**

1E-6/f with f the frequency measured

General frequency source

Averaging time : 1000 s

Approved on 31 August 2021

Frequency ,
Frequency
:
**0.01 MHz to 350 MHz**

General frequency source

Relative expanded uncertainty
:
**2.0E-12 Hz/Hz**

Direct frequency measurement

Averaging time : 1000 s

Amplitude : 1 to 5 V (50 ohm)

Approved on 31 August 2021

Acoustics, Ultrasound, Vibration

This metrology area covers the fields of acoustics, ultrasound and vibration.

Electricity and Magnetism

This metrology area covers the fields of DC and AC measurements, impedance, electric and magnetic fields, radiofrequencies and measurements on materials.

Length

This metrology area covers the fields of laser frequencies and dimensional metrology.

Mass and related quantities

This metrology area covers the fields of mass standards, force, pressure, density, hardness, torque, gravity and viscosity.

Chemistry and Biology

This metrology area covers all fields relevant to chemistry and biology.

Ionizing Radiation

This metrology area covers the fields of dosimetry, radioactivity and neutron measurements.