Profile: Turnkey Instruments Ltd. manufactures industrial and scientific instruments. We produce a range of environmental monitors, off-road brake testers, road vehicle brake testers and window tint testers. Environmental monitoring are primarily for measuring levels of dust & other airborne particulates, though also record ambient temperature & relative humidity, and wind speed & direction using an attachable anemometer. The monitors use a light scattering technique to measure different dust particle sizes simultaneously, recording TSP, PM10, PM2.5 and PM1 fractions. The simret 3000 brake tester simplifies the routine testing of heavy vehicle, locomotive and braking systems. The display indicates brake efficiency.