Tom Parry Jones, who has died aged 77, was a Welsh scientist who developed the world's first electronic breathalyser in 1974 and sold the product to police forces around the world. The origins of the breathalyser go back to 1927, when a police surgeon in Marlborough persuaded a suspect to inflate a football bladder by breathing into it. By measuring the ethanol content of the exhaled air, the surgeon was able to testify in court that the man was "50pc drunk".
In 1954, Robert Borkenstein, a captain with the Indiana State Police, invented the first "breathalyser", a device consisting of a tube containing chemical crystals attached to a plastic bag, the crystals undergoing a colour change dependent upon the level of alcohol detected in a suspect's breath.
When the British government introduced the Road Safety Act 1967, which defined the maximum level of alcohol a person could have in his or her body while driving and introduced the roadside "breathalyser" screening test, Parry Jones established a company, Lion Laboratories, in a converted garage in Cardiff to make the "Alcolyser" crystal-filled tubes for these early products.
The 'tube and bag' breathalyser, which used coloured crystals, came into operation in Ireland at midnight on November 2, 1969, amid widespread fears that it would impinge on motorists' rights – following hot on the heels of the nationwide 60mph speed limit – and impact on publicans' Christmas trade.
Its arrival was used by some cunning traders as a marketing ploy with the Gresham Hotel advertising its 1969 New Year's Eve package under the heading 'Beat the Breathalyser: Don't drive home – why not stay'.
While Britain set its legal limit at 80 milligrams of alcohol per 100 millilitres of blood, and Sweden at 50, Ireland's Road Traffic Act set the legal limit at a blood level of 125 milligrams – which, according to the state pathologist, corresponded to some four-and-a-half glasses of whiskey (depending on the drinker's weight).
The first convictions based on breathalyser evidence were secured in Cork but the equipment was dogged by difficulties and its use was suspended on and off over the next 10 years due to legal wranglings and lack of co-operation from medical professionals reluctant to administer follow-up blood and alcohol tests in 'unhygienic' country garda stations.
It was Parry Jones's more advanced, portable 'Alcometer', showcased at the National Road Safety Association's stand in the 1977 Spring Show, that truly revolutionised the war against drunk driving. It was introduced in Ireland in 1988 and is now marketed worldwide.
He began examining the possibility of developing a fuel cell alcohol sensor as the basis of a more reliable screening instrument in 1972. His electronic device, the size of a cigarette packet, transformed the process of screening by removing the need for a follow-up blood or urine test.
However, it took some time to catch on, and Parry Jones recalled that he found "inventing the device the easy part, but producing it, developing it and selling it was the challenge".
The son of a farmer, Thomas Parry Jones was born on March 27, 1935, and grew up in Anglesey. After taking a degree in chemistry at Bangor University in 1958, he took a doctorate at the University of Alberta, Canada. Returning to Britain, he was appointed a lecturer at the Royal Military College of Science at Shrivenham, Oxfordshire.
In 1964 he moved to the University of Wales Institute of Science and Technology at Cardiff where, with his colleague Bill Dulcie, an electrical engineer, he formed Lion Laboratories in 1967. In 1991 the company was sold to the American technology giant MPD.
Parry Jones also served as chairman of the Snowdonia Business Innovation Centre, which helps companies to commercialise products and technology; as president of the Welsh Centre for International Affairs; and as a trustee of the Engineering Education Scheme for Wales.
He also established an endowment fund at Bangor University to encourage young people to pursue careers in science and technology.
He was appointed OBE in 1986. He is survived by his wife Raj and by a son and two daughters from a previous marriage.