This article presents an upgraded LUDLUM Scaler Ratemeter Model 2200 into a nucleonic thickness and level gauge. A vertical pipe scanning, consisting mediums such as SS-316, sand, wax, polyethylene, oil, water and air (empty) was done at Malaysian Nuclear Agency, Bangi, Selangor in order to obtain a shielding data as well as the corresponding voltage signals at the ratemeter. A simple comparator circuit with reference potentiometers and LED indicators was then designed and fabricated to work as a thickness or level gauge. The reference can be adjusted in accordance to type and thickness of the pipe/ container, the source intensity of X or Gamma ray, diameter of the pipe and also the distance between source and the NaI(Tl) detector.