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Laurie Christian

Laurie Christian

Scientist

Electrical Standards

Contact Details

Areas of Expertise

  • Electrical metrology but specializing in DC voltage and current
  • Mains frequency power
  • Resistance

Qualifications: 

PhD (Physics) University of Otago

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Biography:  

Laurie has 30 years of experience as an electrical metrologist with active involvement in the quantum electrical measurement revolution. When he joined the laboratory in 1978 the New Zealand DC voltage standard was based upon the traditional Weston standard cell.  Now the voltage standard is orders of magnitude more accurate, being based upon a commercial superconducting chip comprising 20,000 Josephson junctions immersed in liquid helium at 4.2 K.  He has researched the origins of the complex and at times temperamental behaviour of these Josephson chips reported by their users.  This understanding led in 1995 to a provisional patent for a new technique for the fast switching of Josephson junctions.  The application is arbitrary waveform synthesizers that exploit the stunning accuracy of the Josephson effect.  The patent was allowed to lapse but the invention led to him working in 1997 at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, researching new Josephson device applications.  The downside of quantum electrical standards is their requirement for cryogenic cooling and this has required Laurie to gain expertise in this technology area.  As part of this in 1985 he carried out a significant redesign of the joint VUW/IRL helium liquefier.

As leader of a small team comprising seven electrical metrologists Laurie gets involved in a wide range of electrical measurements and this is useful in his role as a technical assessor for ISO 17025 accredited calibration laboratories.   Apart from Josephson technology, his research interests have included better measurement of DC voltage, high DC current, and mains frequency power.  In the latter area he is well known to the staff of the New Zealand Meter Test Houses through his providing a two day Traceable Electrical Energy Metering workshop.

Laurie in his spare time dabbles with the uncertainties of golf and enjoys spending time with his family and his local church community.

Professional activities:  

Member of New Zealand Institute of Physics, Metrology Society of Australia, and New Zealand delegate on the Consultative Committee for Electricity and Magnetism.