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How to get a roller skating driver's license
The certificate of the roller is not a driver's license, but an operation certificate. It should be issued by the labor department or the agricultural machinery department, and the examination should be conducted in the institution that issued the operation certificate. ?

Roller, also known as compactor, is a kind of road construction equipment. Roller belongs to the category of road construction equipment in construction machinery, and is widely used for filling and compacting large-scale projects such as high-grade highways, railways, airport runways, dams, stadiums and gymnasiums.

Sand, semi-viscous, cohesive soil, subgrade stabilized soil and asphalt concrete pavement layer can be rolled. Because of the gravity of the machine itself, the roller makes the compaction layer permanently deformed and dense, which is suitable for all kinds of compaction operations. Roller is divided into steel wheel type and tire type.

Low temperature effect:

The low temperature makes it difficult to start the engine. The main reasons are the increase of lubricating oil viscosity, the decrease of battery working ability and poor fuel atomization.

The viscosity of engine oil increases with the decrease of temperature, and its fluidity deteriorates, which makes the lubrication condition of engine worse and the rotation resistance of crankshaft increase.

When the battery is at low temperature, the viscosity of the electrolyte also increases and the permeability decreases. With the increase of internal resistance, the battery capacity and terminal voltage decreased obviously, and even it could not be discharged. The voltage drop makes the starter unable to obtain the required output power and it is difficult to meet the requirements of starting speed.

Because of the low temperature, low crankshaft speed, low intake pipe temperature and gas flow, and poor fuel atomization quality, it further increases the difficulty of engine starting.