Objective The measurement of very low humidities of gases is an increasingly important problem, particularly in the microelectronics industry, where water is the most common contaminant of ultra pure gases. A residual water content of 1 ppb (dew point -112(C) is now demanded in some manufacturing processes, so reliable methods of measuring such low moisture levels are required. Especially at low dewpoints, state-of-the-art humidity sensors lack measurement accuracy, sensitivity and stability. They are also slow in responding to humidity changes, and hence are unsuitable for on-line process control. A mass spectrometer (APIMS) is the most reliable system for measuring low humidity, but is unsuitable as a transfer standard because of its geometrical dimensions and high cost. A cheaper, more readily transportable system could offer great advantages as a secondary transfer standard. This project proposes to adapt advanced infrared absorption spectroscopy methods using FM-modulation techniques to detect very low humidities at atmospheric conditions. The absorption method permits very fast measurements, thus facilitating on-line process control provided equilibration of the apparatus is achieved with respect to trace quantities of water. The resulting instrument would be valuable for national standards laboratories and industrial laboratories throughout the European Union for the reliable measurement of humidities at very low levels. There is currently no recognized standard below a dewpoint of about -80 (C, but the instrument could assist the development of an international transfer standard with traceability of the measurement through accredited laboratories. To develop the infrared absorption humidity sensor, an international team of 6 partners and 2 subcontractors has been brought together. The partnership includes a university and a national standards laboratory which will together undertake the actual development work. Major tasks are the test and selection of a suitable frequency modulated diode laser and low-noise detector, as well as the design of a measuring cell, with all associated electronics and software. Four national standards laboratories will test the instrument and assess its performance against established techniques, with a view to the traceability of the measurement. An industrial partner interested in gas purification down to impurity levels better than 1 ppb will also assist in the assessment of the instrument and establishing appropriate specifications. Fields of science engineering and technologymechanical engineeringmanufacturing engineeringnatural sciencesphysical sciencesopticsspectroscopyabsorption spectroscopyengineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensorsnatural sciencesphysical scienceselectromagnetism and electronicsmicroelectronicsnatural sciencesphysical sciencesopticslaser physics Programme(s) FP4-SMT - Specific research and technological development programme in the field of standards, measurements and testing, 1994-1998 Topic(s) 02 - Research related to written standards and technical support to trade Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator UNIVERSITY OF ERLANGEN-NUREMBERG EU contribution No data Address Cauerstrasse 4 91058 ERLANGEN Germany See on map Total cost No data Participants (5) Sort alphabetically Sort by EU Contribution Expand all Collapse all Bundesrepublik Deutschland Germany EU contribution No data Address 388,Fürstenwalder Damm 12587 Berlin See on map Total cost No data Instituto Nacional de Técnica Aeroespacial 'Esteban Terradas' Spain EU contribution No data Address KM 4,Ctra. Ajalvir 28850 Madrid See on map Total cost No data NMI B.V., INSTITUTE FOR METROLOGY AND TECHNOLOGY Netherlands EU contribution No data Address 97,Schoenmakerstraat 97 2600 AR DELFT See on map Total cost No data National Physical Laboratory (NPL) United Kingdom EU contribution No data Address Queen's Road TW11 0LW Teddington See on map Total cost No data Saes Getters SpA Italy EU contribution No data Address Viale Italia 77 20020 Lainate Milano See on map Total cost No data
