This website from australia feature several good projects like digital insulation meter and high voltage meter which is a little expensive for the technician like us to buy. In this site they teach us how we can make one like the high voltage meter.You may read the whole article by subscribing to their magazine. You may type link on your browser www.siliconchip.com.au. If you are on their website go to project to build.The picture are from the same website.