The article is devoted to improving the accuracy of the system for measuring and controlling the level of liquid materials in horizontal cylindrical tanks. The task of ensuring continuous accurate control of the level, volume and mass of petroleum products, taking into account the shape of the bottom of the tank, is set. In order to improve the accuracy of the measuring device, a laser rangefinder is installed, which allows you to determine the distance from the tank lid to the point of the surface level of the liquid product and calculate the volume of the liquid material by determining the average temperature and correcting for temperature changes when calculating the density, volume and mass of petroleum products with different shapes of the bottoms of a horizontal cylindrical tank. The developed method provides high accuracy, low power consumption, implementation is simple and economical. The device has no mechanically moving parts, so the measuring equipment is protected from failures and has a long service life.