Asia Pacific Metrology

Programme (APMP)

TCTF 2019

Sydney, Australia

Standards and

Calibration

Laboratory (SCL)

Hong Kong, China

Brief Introduction of SCL

Functions of SCL

Establishing and maintaining the reference standards of physical measurement traceable to the International System of Units (SI) for Hong Kong

Ensuring these standards are recognized worldwide

Providing calibration services to disseminate the values of these standards

Disseminating metrological knowledge through other customer services

volt

(volt, V)

Josephson Array Voltage

Standard

resistance

(ohm, Ω)

Quantum Hall Resistance Standard

length

(metre, m)

Iodine Stabilized

Helium-Neon Laser

thermodynamic temperature

(kelvin, K)

Triple Point of Water Cell

mass

(kilogram, kg)

Copy No. 75 of the

International Prototype of

Kilogram

time

(second, s)

Caesium Beam Atomic

Clock

luminous intensity

(candela, cd)

Cryogenic

Radiometer

electric current

(ampere, A)

Primary Standards at SCL

Quality System of SCL

The Quality System of SCL complies with:

ISO/IEC Standard 17025:2017

HOKLAS Accreditation Criteria, Doc. 003

SCL System accredited by National Measurement Accreditation Services (or UKAS today), 1985 -1994

SCL System accredited by HOKLAS since 1994

Accreditation

SCL Participation in International MRA

SCL as Signatory to the Mutual

Recognition Agreement of the

International Committee of

Weights and Measures (CIPM

MRA) (Since 10 June 2000)

SCL Calibration & Measurement

Capabilities (CMCs) listed in

Appendix C of the CIPM MRA for

international recognition (Since

26 Jan 2001)

SCL authorized to use the CIPM

MRA logo on its certificates of

calibration (Since 20 September

2006)

Measurement Parameter (in alphabetical order) CMCs AC voltage, current, and power 12

DC voltage, current, and resistance 20 Density 6

Dimensional metrology 13 Force 4

Frequency 14 High voltage and current 4

Humidity 2 Impedance up to the MHz range 6

Laser frequencies 2 Mass, mass standards 9

Other DC and low frequency measurements 3 Pressure 6

Radio frequency measurements 21 Sound in air 15 Temperature 28 Time interval 14

Time scale difference 1 Torque, Viscosity, Hardness and Gravity 9

Total: 189

SCL CMCs published on BIPM website http://kcdb.bipm.org/AppendixC/

Calibration Services of SCL

• Electromagnetism (DC, LF, RF & Magnetism)

• Time and Frequency

• Temperature and Humidity

• Photometry & Radiometry

• Acoustics & Vibration

• Length Metrology

• Mass and Related Quantities

Time and Frequency Measurements

at SCL

Recent Development

• SCL received the time link calibrated values of P1 and

P2 from NIM (Group 1 in RMO) in July 2019. We applied

the values to the GNSS receiver for generating the

CGGTTS file.

• SCL acquired a spare multi-frequency multi-system

GNSS receiver in December 2018.

• SCL plans to acquire a hydrogen maser frequency

standard in FY 2020/21.

Recent Development

• Two more RF coaxial cables will be installed between RF

Lab at 36/F and roof top at 48/F in December 2019.

They will be used for time link calibration.

SCL on 36/F

GPS Antenna on 48/F rooftop

Status of Comparisons

• SCL completed the measurement of the artefact for the

APMP TCTF Stopwatch Calibration Comparison.

CMC Activities

• Up to October 2019, the SCL has 29 TF related

entries listed in the BIPM - Calibration and

Measurement Capabilities – CMCs (Appendix C)

Quantity Instrument or Artifact

Measurement method Measurand Minimum value

Measurand Maximum value

Time scale difference

Local clock vs UTC Direct time interval measurement against UTC(SCL) using

calibrated counter 1.0E-9 1.0

Time interval

Time difference source

Direct time interval measurement using calibrated counter 1.0E-9 s 999 s

Time difference meter

Measuring test signals from calibrated generator 1.0E-9 s 999 s

Period source Derived from direct frequency measurement using calibrated

counter 38 ps 1 s

Period meter Measuring test signals from calibrated period source 38 ps 1 s

Frequency

Local frequency standard

Phase comparison with laboratory frequency standard

10.0 MHz 10.0 MHz

5.0 MHz 5.0 MHz

1.0 MHz 1.0 MHz

100.0 kHz 100.0 kHz

General frequency source

Direct frequency measurement using calibrated frequency counter

1.0 Hz 26.5 GHz

Frequency counter Measuring test signals from calibrated frequency source 1.0 Hz 26.5 GHz

Quality Matters

• Peer review in the technical area of Time and Frequency

was conducted by Prof. Aimin Zhang from National

Institute of Metrology, China in December 2018.

International Technical Activities

• Design of a Synchronous Counter with Two-dimensional

10 x 10 LED array for Calibration of Timing Parameters

of Video Cameras

– 2019 URSI Asia Pacific Radio Science Conference in

New Delhi, India.

R9

C0

R0

R1

R2

R3

R4

R5

R6

R7

R8

C1 C2 C3 C4 C5 C6 C7 C8 C9

Vcc

47 Ω

3.3 kΩ

3.3 kΩ

47 Ω

9015B

C7

C8

D10

A0

A1

A2

1

2

E3

Y7

GND

Vcc

Y0

Y1

Y2

Y3

Y4

Y5

Y6

A2

74

HC

13

8

C0 C1 C2 C3 C4 C5 C6

D11 D12 D13

C9

A0 A1 A2 1 2 E3 Y7

GND

Vcc Y0 Y1 Y2 Y3 Y4 Y5 Y6

A1

74

HC

13

8

Vcc Clock

Vcc R7

R8

D00

A0 A1 A2 1 2 E3 Y7

GND

Vcc Y0 Y1 Y2 Y3 Y4 Y5 Y6

B2

74

HC

13

8

R0 R1 R2 R3 R4 R5 R6

D01 D02 D03

R9

A0 A1 A2 1 2 E3 Y7

GND

Vcc Y0 Y1 Y2 Y3 Y4 Y5 Y6

B1

74

HC

13

8

Vcc

Vcc

(i) Circuit diagram for the motion of column LEDs. (ii) Circuit diagram for the motion of row LEDs.

International Technical Activities

• Calibration of Timing Parameters of Still Image Cameras

and Video Cameras by a Two-dimensional LED Array

– 2019 NCSLI in Cleveland, Ohio, USA.

International Technical Activities

• Calibration of the Frame Rate of High-Speed Digital

Video Recorders by Stationary Counting Method:

Application of the Stroboscopic Effect

– NCSLI Measure Journal, Vol 12 No. 2, pp 38–44,

2018.

International Technical Activities

• SCL presented a paper “Investigation of Differences in

Calibration Results for Electronic Clocks using the Time

Base Method and the Totalize Method” in 2019 ATF.

Thank you