1. Generation and development: Liter was a kind of container in ancient times, which was named after the introduction of international volume units from the West. Later, the number of liters made in China became less and less. Liters originated in China and later spread to Japan, the Korean Peninsula, Vietnam and other places.
2. International status: Liter is a non international unit, and liter is an international unit.
3. Concept: In ancient times, liter was a container and a unit of measurement. Liter is the capacity unit of the traditional ruler penetration method in East Asia.
gas station:
The gas station refers to the retail gasoline and engine oil supplement station serving automobiles and other motor vehicles, generally for adding fuel oil, lubricating oil, etc. Because the petroleum commodities sold by gas stations are flammable, explosive, volatile, leaky, and easy to accumulate static charges, gas stations take safety as the first criterion. It is strictly prohibited to smoke and fire in the gas station, to engage in operations that may produce sparks, and to fill the carburetor and the side bucket of the car with gasoline. All stations must shut down the fire before entering the station for refueling, and all dangerous goods are strictly prohibited from entering the station. Fuel dispenser is an oil metering device that directly refuels vehicles. It forms a complete oil supply system with oil tanks, pipelines, pipe fittings and valves. The fuel dispenser is composed of four assemblies of oil pump, oil-gas separator, metering device and counter, as well as some other components such as motor and oil gun. Any fuel dispenser can be regarded as composed of this assembly and some other simple components. There are many types of fuel dispensers used by gas stations, ranging from mechanical, electronic to computerized automatic fuel dispensers. The flow of the fuel dispenser can be divided into 50-60 L/min and 80-90 L/min. Small flow fuel dispenser is suitable for fueling cars and vans; The large flow fuel dispenser is suitable for the refueling of large buses and container trucks. The basic structure (mechanical transmission part) of various fuel dispensers is consistent. The difference between mechanical type and electronic type is that the digital display device is different. The electronic type can be used together with the microcomputer to achieve the purpose of automatic operation.