Classes of accuracy represent characteristic of measuring means which is necessary for check of their compliance to state standards. Any errors or changes of parameters capable though so to affect device accuracy are provided in classes of accuracy. Classes of accuracy describe limits of deviations, admissible within the standard, from the reference size or value. Operating by accuracy classes substantially facilitates check of measuring funds for compliance to standards.

Liquefied natural gas is demanded in various spheres of activity of the person - in the industry, in the road transport, in medicine, in agriculture, in science and so forth. Liquefied gases won considerable popularity due to convenience of their use and transportation and also ecological purity and low cost.

Work of your car depends on quality of engine oil. It has to approach a make of the car and type of the engine. Important criterion is the viscosity of oil how to define it?

Gas and oil play the huge role in modern economy. Their production is the difficult process demanding the thorough choice of a necessary method and the equipment. The final decision is made on the basis of a set of factors.