Roofing and hydraulic-insulating flexible bitumen-based and polymeric (thermoplastic or elastomer) materials. Method for determination of watertightness after stretching at low temperature
State system for ensuring the uniformity of measurements. State primary standard and all-union verification schedule for means measuring volumetric flow of gas within the range of 1x10 in minus 6 up to 1x10 in 2 degree m3/s