Lux meter is a tool used to measure the amount of light intensity in a place. The amount of light intensity needs to be known, because basically humans also need adequate lighting. A good operation lamp should qualify that has been specified based on laws that issued by kemenkes, Sufficient lighting for operating rooms is 300-500 Lux and for operating desk is 10,000-20,000 Lux. Testing the accuracy of the measurement results in this tool, the authors compare the value of light intensity of the authors tool with the value of light intensity using lux meter in Rumah Sakit PKU Gamping. Data measurements have been tested 20 times at a distance of 1 meter and 20 times at a distance of 1.5 meters. Based on the measurement and comparison of data, it can be concluded that between the author and comparator has the error and the difference is relatively low, the error that obtained is 0.01% at a distance of 1 meter by 2 lux difference, and an error of 0.23% at distance of 1.5 meters by 24 lux differences. For distance measurement and timer on authors tool obtained error 0% by 0% difference.