FIELD: measurement technology. SUBSTANCE: examined liquid is placed into closed vessel and is transferred to overheated state. Overheating degree is set sufficient for registration of $$$ particles. Life time of metastable state of liquid is used to determine $$$ activity of liquid. If there is no $$$ radiation in liquid, overheating degree is established equal to value at which registration of $$$ particles occurs. $$$ activity of liquid is determined by life time of its overheated metastable state. EFFECT: enhanced authenticity of process. 7 cl
