Heating boilers. Part 4. Heating boilers with forced draught burners. Special requirements for boilers with forced draught oil burners with output up to 70 kW and maximum operating pressure of 3 bar. Terminology, special requirements, test methods and marking
State system for ensuring the uniformity of measurements. State verification scheme for measuring and reproduction instruments of sound pressure in water within frequency range from 1·10 -3 to 1·10 6 Hz
