Laser pressure sensors being developed at Oxford University could lead to cleaner, more efficient, petrol engines.
The usual means of measuring pressure relies on a transducer in the wall of the vessel containing the gas which only responds when the pressure wave has expanded to fill the chamber. The technique developed by the team can, in principle, detect the localised pressure rise before it is felt at the wall.
Professor Paul Ewart, leader of the non-linear optics and combustion physics group and director of the Oxford Institute of Laser Science, said: "We have demonstrated a technique by which both the temperature and pressure can be measured simultaneously at a point in time and space.
"So a transient change in temperature and pressure occurring in a small region of space can be detected and measured."
The changes measured by the sensor typically occur during ignition or explosions of gases. Being able to detect pressure in this way is an important step towards understanding such phenomena as auto-ignition in petrol engines.
It can also be applied to other transient phenomena involving shock waves, chemical explosions and so on.
Prof Ewart said: "Our technique is not only the most accurate method for measuring temperature of gases non-intrusively and remotely, but also the only way of measuring pressure with time and space resolution."
The results, presented at the IoP Photon02 conference in Cardiff, were achieved during the past few months. The team plans to apply the technique in a firing engine as part of research in making engines more efficient and less polluting.
Prof Ewart said: "Understanding better the chemistry of ignition will assist the design of fuels and engines for reducing emission of greenhouse gases."