Quality Alchemist (品質煉金術師): Metrology Symposium 2021 (Metrology Around Us)

The Government Laboratory (GL), Hong Kong Council for Testing and Certification (HKCTC), Open University of Hong Kong (OUHK) and Standards and Calibration Laboratory of Innovation and Technology Commission (SCL) jointly organized the online Metrology Symposium 2021 on 28^th May 2021. The theme is “Metrology Around Us”. Hong Kong Society for Quality (HKSQ) was one of supporting organizations. The seminar aimed to share selected several interesting topics around our daily life and the recent development in the transformation of the International System of Units (SI) to the digital world led by the International Committee for Weights and Measures (CIPM). Group photo was took after welcoming address and opening remarks.

The first speaker was Mr. Brian HT Lee (Electronics Engineer, SCL) and his topic entitled “Can we use a smartphone as a luxmeter?” In the beginning, he asked us to think a student proposed to measure the plant’s growth rate against light condition using luxmeter. Is this measurement method appropriate?

Then he introduced basic theory of photometry and radiometry, as well as photometric units. Some daily life examples of luminous flux were discussed.

Finally, Mr. Lee compared the key components in smartphone and instrumental luxmeter. The key difference was the acceptance angle that the smartphone luxmeter reading is dropped by ~10% to the instrumental luxmeter.

The second speaker was Dr. Alvis CF Au Yeung (Electronics Engineer, SCL) and his topic named “Is time running at the same rate at different places in Hong Kong?” Dr. Yeung shared the content including definition of second, Caesium and optical clock as well as general relativity theory.

Firstly, Dr. Yeung briefed the definition of second, SI base unit of time. It used the fixed numerical value of the caesium frequency to express the unit Hz (s^-1).

Then he briefed the general relativity theory and Lorentz time dilation named after the Lorentz transformation that related the space-time coordinates. And he introduced the effect of the gravitational time dilation. He showed the different altitude in Tai Mo Shan and Avenue of Stars.

Finally, Dr. Yeung calculated the atomic clock runs 9ns faster per day at Tai Mo Shan.

The third speaker was Dr. Jasmine PK Lau (Chemist, Government Laboratory) and her presentation was “Chemical Metrology – Supporting the quality of life”. She briefed different measurement around us such as GPS, Medical Devices, Chemistry Instrument, etc.

And then she introduced the traceability that metrology had appeared in ancient civilizations. For instance that Egyptians defining a standard unit of length for building the Pyramid and ancient Chinese using Jia-liang for measuring several volumetric standards.

Lastly, she introduced the metrology related legislation in Hong Kong including Chapter 68 Weight and Measures Ordinance, Chapter 214 Metrication Ordinance, as well as, Chemical Metrology in Hong Kong that Government Laboratory (GL) was a designated institute under the CIPM MRA since May 2005.

Before the break, a video of SCL was showed.

Dr. Eric TP Sze (Associate Professor, OUHK) was the fourth speaker and his presentation title named “Measurement to assist in fighting pandemics”. Firstly, he raised some examples such as diagnosis of positive / negative cases, conformity of PPE (e.g. face masks), calibration of infrared thermometers, vaccines development, etc.

The first topic Dr. Sze shared was the filtration efficiency of face masks that ASTM F2101-19 standard test method for BFE was introduced and compared different type of medical face masks.

The second topic Dr. Sze shared was chlorine content in bleaching solutions. The key active ingredient in chlorine bleach was Sodium hypochlorite (NaCIO) that bleach contained 5.25% sodium hypochlorite. Usually, it employed titration method to test chlorine content in bleach.

Mr. Raymond WM Leung (Electrical and Mechanical Engineer, SCL) was the fifth speaker and his topic entitled “The story of gravitational acceleration at Hong Kong, the equator and the poles”. He briefed Newton’s law of universal gravitation (the big G and the little g) in the beginning.

The measurement of gravity became important not only to the geodesists, but also to metrologists in the measurement fields of force, torque and pressure which rely on applying force due to the earth’s gravity on a known mass, in air. The equipment generation of known force was showed.

Since earth is not perfect sphere and reduction in g due to earth’s rotation, some factors should be added into the equation for estimating the value of g.

Finally, Mr. Leung introduced SCL on-site measurements the value of g and showed their new equipment in 2019.

Mr. Cliff SH Wong (Electronics Engineer, SCL) was the last speaker and his presentation named “Metrology coming to the digital age”. In the beginning, Mr. Wong briefed industry 4.0 and smart factory.

Then he briefed the cross between Metrology and Digitalization. The Digitalization in metrology key objectives were mentioned that including uniformity, usability, holistic approach and efficient workflows.

And then Mr. Wong shared guiding principles for the management of scientific and research data named FAIR stands for Findable, Accessible, Interoperable and Reusable. The digital SI framework (D-SI) was launched by CIPM in 2019 and the digital object identifier based on ISO 26324. The data property summary was showed in the diagram below.