Tankers are the main equipments in gas station, which play an overall role in delivering oil, measuring and guaranteeing oil supply. There are many kinds of tankers, and according to the difference of counting indicator, they can be divided into three categories: mechanical tankers, electronic tankers and computer tankers.
  Mechanical tankers adopt mechanical counters, and electronic tankers replaced mechanical counters with electronic counter, adding electro-optic sensors, while computer tankers adopt computer controlling counters. Computer controlling counters add calculation, control, price calculating, and refueling with preset liter of oil and preset amount of money function, except completing simple counting work under the control of CPU microcomputer. In addition, computer tankers have many functions such as total accumulating display and preservation of liter and money, display function while losing power, placement of oil during shutdown of computer and valve in advance, communicate with the computer and accept computer instruction.