William Roderick Blevin

Biography

William Roderick Blevin was born on 31 October 1929, at Inverell, New South Wales. His mother Elizabeth McRae was born in 1894, and grew up on a property Ferndale some 56 kilometres east of Armidale in the New England area of New South Wales and lived there until her marriage. His father, also William, was born in 1888, and became at the age of 15, a pupil-teacher (a primary schoolteacher, without any real, formal training), up in the north-west of New South Wales.

Bill completed his secondary schooling at Tamworth High School (1945) before deciding, in a circular fashion, to study at New England University College to become a science teacher. He obtained his BSc (Hons 1) in 1950; his DipEd in 1951 and his MSc in 1952, all from the New England University College, Armidale, New South Wales, then part of the University of Sydney. He was awarded a DSc from the University of New England in 1972.

From 1950 to 1951, he worked as a Research Assistant (part-time) in Physics at New England University College and in 1953 joined the CSIRO Division of Physics as a Research Scientist and leader of the optical radiometry group. As Bill recalled in the interview with Neville Fletcher (see Sources below):

Well, it was my own decision. Somerville [JM Sommerville, his boss] was still away at Swansea; I didn’t communicate with him about it and I probably should have done. I think he was disappointed. But I had been told by various people that you shouldn’t stay too long in the institution where you do your first degree. Of course, the done thing was to do a PhD. In those days you could not do a PhD in any Australian university and I didn’t really think, with my economic circumstances, there was any way I could get away to do a PhD overseas. But I still had this in my mind: that I should be getting out into a bigger pool than what was a quite small physics department at Armidale.

So I applied for two jobs, both with CSIRO and both in Sydney. One was with the National Standards Laboratory (NSL) on the Sydney University campus, and the other was with a new Division just being set up, which was the Division of Wool Physics at Ryde. This was being set up by

Somerville, when he came back, told me things I didn’t know. It just shows that I hadn’t been very inquiring, I suppose. He said, ‘Well, you know, we expect to get autonomy in just one more year.’ If I’d stayed on one more year, NEUC would have become the University of New England. And he thought that I needed only about one more year of research and I’d have enough research to put in a PhD thesis. All the universities in Australia were about to start awarding PhDs. Anyway, it was too late for me, but my younger brother, Harry, went on to gain BSc (Hons) and PhD degrees in physics at UNE, under Somerville’s supervision.

Bill Blevin remained at CSIRO for forty-two years, until his retirement in 1994. He was promoted to the rank of Chief Research Scientist in 1976, Chief Standards Scientist and Assistant Chief of Division (1980-88) and finally Chief Standards Scientist and Chief of Division of Applied Physics (1988-94).

The National Standards Laboratory

Prior to the war, most of CSIRO’s work had been in biological sciences. Just before the war, not to do with the war but independently, CSIRO decided that it should get more into physical sciences and one of the first things recommended was to set up a national standards laboratory that would maintain Australia’s physical standards of measurement. The NSL would be the final arbiter as to how long a metre was, how long a second lasted and all sorts of units, including nuclear quantities, etc.

NSL quickly became the leading organisation in Australia’s national measurement system, collaborating closely with the National Standards Commission (NSC) involved in legal metrology, the National Association of Testing Authorities (NATA) involved in laboratory accreditation, the Standards Association of Australia (SAA) involved in documentary standards, and the States’ Offices of Weights and Measures which took care of trade measurements.

In April 1945, NSL was restructured into three Divisions of CSIRO – the Division of Metrology, dealing with length and mass, etc; the Division of Electrotechnology and the Division of Physics.

Research interests

Photometry, Radiometry and Colorimetry

The group Blevin was asked to lead was the optical radiometry group which was concerned with the three related fields photometry, radiometry and colorimetry. As Bill recalled:

I was attracted by being in some area of physics that had immediate and varied applications. I reported to a chap by the name of

One of my first jobs was to supervise and participate in the calibration of some hundreds of these lamps which were of different powers and operated at different filament temperatures. I immediately found some scope for research because tungsten filaments in new lamps are unstable things and, when they are first operated, they recrystallise. So I set myself the problem of deciding whether in order to stabilise them, it was best to do what other people had done and run them at the temperature they would finally be operated at? Or could you do it, and perhaps even do it better, by using a lower temperature and a longer time? That turned out to be an interesting area of research. We had people in the Division who were quite good on metal physics and could give me some guidance. That was my first published paper out of the National Standards Laboratory and it got quite a bit of attention around the other standards labs.

The range of interest in these subjects was extensive and was far from limited to just providing standards for Australian lamp manufacturers. For example, they collaborated extensively in:

• the development of improved street-lighting technology
• more effective colour signals for road traffic, airport runways and maritime applications
• encouraging and assisting a wide range of manufacturers to adopt physical rather than visual methods to control the colour of their products
• assisting work on the development of deep-sea photometers to measure light deep under the water
• supporting people who were researching aurorae in Antarctica and wanted accurate calibration of an artificial aurora that they had made as a reference standard.

As Bill recalled: You had to sit in the darkroom with it for half an hour before you could even see it and then they still wanted to know how bright that was, in the photometric units. With the Vietnam War, I remember the great trouble that the military had in measuring some of their high-intensity flares that were shot high in the sky and lit up the countryside, and we were able to sort out what was wrong with their apparatus.

Another activity, that had started in Giovanelli’s day, was measuring the haemoglobin content of blood for the Red Cross Blood Transfusion Service in Sydney. They serviced not only all of Australia but also the neighbouring regions and needed access to very accurate spectral measurements. Blevin’s group helped to maintain the haemoglobin standards for years. Later on, using a new method developed overseas haemoglobin levels were measured by treating the blood sample with hydrogen cyanide, to generate cyanmethaemoglobin, which had the advantage over oxyhaemoglobin of being extremely stable (for months). As Bill Blevin recalled:

Our measurements contributed to the internationally adopted value for that, and I must say that led to my one and only paper ‘a shared paper’ in the Lancet. It’s nice to be able to say you have had a paper published in the Lancet. I always like telling my GP: ‘When I published in the Lancet‘. Anyway cyanmethaemoglobin was so stable that it was developed as a commercial product, although not by us but in America. There was no need to have us involved in haemoglobinometry any longer so that’s when we bowed out of that field.

Bill was also asked to develop a little haemoglobin meter so that surgeons could measure the amount of oxygen being put into the blood during open-heart surgery.

In 1959, Bill visited most of the major international standards labs, starting off with Japan, then India, Russia, Britain and several places in Western Europe and, eventually, the United States and Canada. He visited a number of lamp manufacturers, such as the General Electric Company in England, Siemens and Philips in Europe, and GE in America; and laboratories that were interested in physical colour measurement, such as ICI and Imperial College.

Contributions to optical radiometry

Bill made significant contributions to the field of optical radiometry, the measurement of radiation without worrying about vision. As Bill Recalled:

In the late 1950s, optical radiometry was in a pretty poor state. I thought to myself, ‘Well, if we can’t measure radiation in ordinary physical units to determine how much power there is in watts or microwatts or whatever, it’s surely going to be harder to do the equivalent measurement while also allowing for the curves that control vision.’ It seemed to me that it was important that we learn to measure radiation better. In other words, it did persuade me to spend several years concentrating on radiometry rather than photometry. Although we had to keep up with the photometric needs of our customers. I might say that Giovanelli was opposed to that. He said, ‘Oh, that’s an old classical subject’, and I said, ‘Yeah, but we’re no good at it; nobody’s any good at it.’ Anyway, he gave me my head, so we did quite a lot of work improving radiometry.

Previously we had used overseas standards for radiation measurement but now, for the first time, we had developed some Australian standards that we had more faith in.

Subsequent unforeseen applications for optical radiometry were experiments to determine if lasers were safe and measurement of the power being transmitted through optical fibres.

Measuring the Stefan-Boltzmann constant

His work on measuring the Stefan-Boltzman constant was described by Bill as the group’s greatest influence on international radiometry. As he recalled in his interview with Neville Fletcher (see Sources below):

This problem had been recognised but unresolved ever since the year 1900 when Max Planck derived his celebrated law governing the spectral energy distribution of the radiation emitted by a blackbody at absolute temperature (T). Some 20 years earlier Stefan and Boltzmann had discovered that the amount of heat emitted by a hot body varies as the fourth power of its absolute temperature. So, if you increase the absolute temperature by a factor of two, the amount of heat radiated goes up 16 times. The constant of proportionality is known as the Stefan-Boltzmann constant. When Plank’s law came out, it became possible to calculate the value of this constant from three other and more fundamental constants. The trouble was that nobody could ever get agreement between the theoretical value calculated from these fundamental constants and the measured value.

That had gone on for 50 or 60 years and reflected adversely on the confidence held in radiometric measurements. It wasn’t a minute disagreement; it was about 1.5 per cent on average and quite often worse than that. So we decided that we’d have a go at measuring the Stefan-Boltzmann constant. It was a very difficult measurement, perhaps the most demanding bit of experimental work that I and my partners undertook, and I must say that in all this work I had partners; one particular partner by the name of Bill Brown did a lot of work with me throughout my career. The measurements had to be done in a vacuum. For the radiation source we developed a cavity radiator (blackbody) operated at the melting point of gold, which is a very dull red sort of a heat, and for the detector a sophisticated electrically calibrated radiometer operated at room temperature.

Many potential sources of error were identified, often common to other areas of radiometry. We even found instances where Planck’s law had been used incorrectly. Further, it was necessary to make a more careful analysis of the bending or diffraction of the radiation beam as it passed through apertures, even ones large enough to be able to put your finger through. There were many such factors to consider but, at the end of the day, our measured value for the Stefan-Boltzmann constant agreed with the theoretical value to within slightly better than 0.1 per cent, and that was about the limit of the accuracy of our measurement.

At that time we happened to have a visit from the then Director of the US National Bureau of Standards, Dr Lewis Branscombe, who was very impressed by the work that we were doing.

At the urging of his Chief of Division Ron Giovanelli, this work was submitted as a thesis for a DSc to the University of New England which was awarded in 1972. At that time it was only the second DSc in physics to be awarded by the University of New England.

Redefining the candela

Another of Blevin’s major achievements while at CSIRO was to have the SI unit of light intensity (the candela) redefined in 1979 to be on a firm physical basis. As Bill recalled:

We decided that we’d done a fair bit for radiometry, and that we should now get back getting photometry onto a proper base. I’d absolutely convinced myself that it was much better working from the receiver end, i.e. the detector end, in both of these fields, rather than dealing with high temperature sources. It was always difficult in practice dealing with high temperature sources. The Consultative Committee for Photometry (CCP) normally met every four years. In 1971, I managed to persuade them that we ought to broaden the name of that committee to include ‘radiometry’, which they did. Also at that meeting I formally proposed for the first time changing the definition of the SI base unit of photometry, the candela, to relate it directly to the watt. The Committee members didn’t agree to that proposal spontaneously, but some of them were interested in it and a few were doing rather similar work already. Anyway, soon after the 1971 meeting, I decided that I was really going to push for this redefinition and make it almost like a mission. It became clear to me that I’d have to persuade at least one of the major standards labs around the world to partner me on this mission.

In 1973, Bill spent a year at the US National Bureau of Standards as what they called an ‘expert consultant’. There he and his colleagues prepared and published a major joint paper, which detailed the case for changing the definition of the candela. As Bill pointed out:

It was a big deal to change the definition of one of the seven base units of the International System of Units (SI). We tried at first to go one step further and get them to adopt the lumen, which is the unit of luminous flux, as the SI base unit, instead of the candela. But we lost that argument out of hand on the grounds that SI was only 20 or 30 years old and not yet fully accepted worldwide. Their view was ‘the last thing we want to do is destabilise it’. It wasn’t for any technical reason, but I could see the merits of their argument.

On the Consultative Committee for Photometry and Radiometry (CCPR) there was some opposition to redefining the candela particularly from the National Physical Laboratory in England and the Russian standards laboratory, the Mendeleev Institute in Leningrad. Eventually, the CCPR did decide in 1977 that it would press for the proposed new definition of the candela to be adopted. Bill recalled that at that meeting the Russian delegation arrived a day late and when he bumped into the leader of their delegation at the meeting she said bitingly, Well, Mr Blevin, I understand you have decided to change the definition of the candela and to see afterwards whether it is a good idea, instead of the reverse order which is the normal case.

The definition of the candela was changed and placed on a firm physical background which allowed the adoption of alternative methods to develop photometric standards, mostly based on detectors rather than sources. Soon afterwards Bill was appointed chairman of the CCPR and a member of the Comité International des Poids et Mesures (CIPM, the International Committee of Weights and Measures), which is essentially the board responsible for the operation of the BIPM.

The redefinition of the candela had a big influence internationally and the number of major labs developing standards for photometry rose from two or three to something like 15 to 20.

Term as Chief of Division of Applied Physics

In 1988, following the major reorganisation of CSIRO, Bill was appointed Chief of the Division of Applied Physics with the job of balancing the standards activities with the industrial research. He re-structured the Division into five research programs with five program managers, an Assistant Chief and himself as the management committee. Each research program had part of the standards responsibility and a range of industrial projects, usually in partnership with a company. At this time, under the initiative of the Institute Director Colin Adam, CSIRO built up a strong relationship with the Boeing Aircraft Company. A number of Divisions, including Applied Physics developed projects with Boeing.

During Bill’s term as Chief the Division also was successful in many projects with local industry. They developed a really first-rate laser device for the Royal Australian Mint, which allowed them to measure rapidly and accurately the profile, or relief map if you like, of the coins and medals, etc. that they manufactured, including the dies used and their rate of wear. Similar instruments were later supplied under contract to the national mints of the USA and China.

The Division made formal agreements with some of the major national labs overseas, recognising the equivalence of their standards and Australia’s. There was quite a bit of interest in offset manufacturing at about that time. One example was the Hughes Aircraft Company which had a big contract making war planes for the Australian government, but the government wanted as much of that business as possible to be subcontracted to Australian companies, one of which was Philips Defence Systems Australia, Sydney. As Bill recalled:

It took a lot of organising and numerous measurement intercomparisons, but we did succeed in getting agreement with the United Kingdom’s National Physical Laboratory and, for defence reasons particularly, with the National Bureau of Standards in the United States, jointly signing very formal statements recognising the equivalence, to within a certain accuracy, of our standards. That certainly did help a lot in procuring some of these offset contracts; although, even then, Hughes Aircraft wanted to do a direct comparison of their standards and ours. We did that once, but then they agreed that it wasn’t necessarily the way to go. They had a very sophisticated lab at Philips Defence Systems and they were kind enough to get me officially to open it. Later we signed similar agreements with the Canadian and New Zealand standards labs.

In the standards area there was regional cooperation with the establishment of an Asia-Pacific Metrology Programme, complementing the worldwide cooperation through the BIPM. As Bill recalled:

The experience in negotiating bilateral agreements with the US, the UK, Canada and New Zealand had clearly demonstrated the impracticality of having a bilateral agreement with every other country, so we had to get more and more into a multilateral sort of system. That got underway in the Asia-Pacific region in some ways faster than it did in Europe or North America, despite the great disparity in the stage of development of the member states. Countries like Vietnam for example at that stage had a pretty rudimentary industry in many ways, but they still needed measurement skills appropriate for their industry and recognised internationally so that their products would be accepted in other countries. That took off rather well. Anyway, it was an interesting occasion.

Retirement and continuing work with BIPM

Bill Blevin retired from CSIRO in 1994. He remained as an Honary Fellow of the Division (now called the Division of Information and Communication Technology) concentrating principally on interactions with the Bureau International des Poids et Mesures (BIPM, the International Bureau of Weights and Measures), located at Sèvres in France. Earlier he had served on the executive of the CIPM, then was Vice-President but, more importantly, after that, Secretary, a more executive position. With much backing from the Asia-Pacific group and particularly Barry Inglis, Terry Quinn and Bill started to set up the guidelines for establishing multilateral recognition of standards and measurement capabilities worldwide, which was a huge effort. As Bill recalled:

We held meetings to get the support of the directors of all the standards labs around the world et cetera. But the decision to proceed was reached by 1998, if I remember rightly, and I understand that in 2009 an international conference was held to review how much had been achieved in 10 years. One of the spokesmen at that conference was a senior executive from Boeing, who said what enormous value the multilateral arrangement had been to Boeing and to their sub-manufacturers. He said that he could hardly have believed that a big modern company like Boeing could gain so much from an initiative under an ancient treaty like the Metre Treaty, which had been signed in 1875.

Then late in the piece I was asked by the CIPM to write the first strategic plan for the BIPM. So a lot of time in my last two or three years was spent on developing a strategic plan for how the measurement system worldwide, but particularly the role of the BIPM, should evolve in the 21st century. Of course this came after consultation with standard labs all around a world. The plan had to go before a General Conference of delegates of the governments of the member states. I’m glad to say that it was adopted.

When I retired from the CIPM in the year 2000, they wanted me to stay on, but I said no, that I wanted to get out before they start asking, ‘What’s that old bugger still doing around here?’ Anyway, they were kind enough to present me with a bound copy of the strategic plan and a nice piece of Sèvres porcelain.

Honours and awards

Bill Blevin received several honours and awards for his scientific contributions. As Professor Neville Fletcher said in his interview with Bill for the Australian Academy of Science (see Sources below):

It’s good to see measurement and standards being recognised for the underlining importance that they have for essentially everything that we do in the way of manufacturing and living. It’s also good to see that you too have been recognised for your contributions to standards and to other branches of physics around the world and particularly here in Australia.

Fellowships

Awards

Committees

Bill served as Secretary to the Australian National Committee on Illumination, and Secretary to the NSW branch of the ‘Institute of Physics and the Physical Society’ whose Chairman was the very distinguished radio astronomer, Dr Joe Pawsey. As Bill recalled:

That was an advantage with coming to a big institution because I got to know Joe Pawsey very well. The two of us would be organising the monthly talks and meetings and so on. He was a delightful man and first-rate physicist, of course. At about that time the decision was made by physicists from around the different states to set up an Australian Institute of Physics, so I was involved in the meetings going on about that.

Other committee positions were:

Positions held

Sources

• Fletcher N, 2010, Interviews with Australian Scientists: Dr William Blevin – Applied physicist (Australian Academy of Science)
• Alafaci A, 2005, Biographical entry: Blevin, William Roderick 1929- (Encyclopedia of Australian Science)