AROUND 6,000 visitors - students, parents, staff and well-wishers - were present at the open day of the Sha Tin Technical Institute of the Vocational Training Council. Workshops, laboratories and special rooms were open to the public, and visitors could join or follow guided tours, exhibitions and talks about the institute's courses. Students of the institute's seven departments presented a wide range of interesting demonstrations. The displays showcased the departments of Applied Science, Commercial Studies, Computing Studies, Design, Electronic Engineering, General Studies and Manufacturing Engineering. In a fourth-floor laboratory and project room, electronic engineering students manned demonstrations with titles like ''Multi-Function LED Banner'', ''Ultra-Sonic Radar'', ''Home Automation System'', ''Voice Mail System'', ''Multi-media Show'' and ''D.C. Motor Control''. In lighter vein was the popular ''Hair Styles Exhibition'', in which visitors were shown a variety of approaches to styling short and long hair. ''Live models'' were available to have their hair cut, shampooed, permed and tinted. Applied Science students made an analysis of road dust, blended liquid detergents and examined bathing beach water. Elsewhere, Computing Studies students had installed a Publishing Company Information System and a Bus Route Enquiry System, while the Manufacturing Engineering Department had come up with a Coin Exchange Machine and a Multi-purpose Foldable Bicycle. A large crowd stopped to admire a model office, set up by the Commercial Studies Department. Elsewhere on the campus, the Civic Education Society had put up display boards covering the influence of cartoons (serial pictures), environmental conservation in Hong Kong and a ''Study Tour to China''. Student counsellors had advice on how to ''Love Yourself'', and a computer game offered a ''Colour Test''. On the ground floor, four classrooms were used to cover the Students' Union (SU) and the various clubs under the SU.