FIELD: measuring equipment.
SUBSTANCE: invention relates to acoustic analysis of electric current generators in vehicles. In the test method, a motor vehicle is placed on a site for research purposes, within the engine compartment open for maintenance at distance of 0.1–0.15 m from the generator housing, a sound level meter microphone is fixed, thereafter, the level of the noise background is measured with the engine of the vehicle under test. At the first stage of research the preheated engine operation is provided at idling mode, after which measurement of total noise level is made, correction is introduced into result of measurements, which is regulated by normative documentation, taking into account level of noise background, and then calculated value of total noise level with standardized maximum permissible noise level are compared. If the calculated value of the total noise level does not exceed the maximum permissible level of noise, then the generator is classified as acoustically sound and studies are completed. If the condition is not met, proceed to the second stage of research, for which the excitation winding of the generator is de-energized and the total noise level is measured again, making the correction specified in the regulatory documentation, taking into account the level of the noise background, then calculated total noise level values recorded at the first and second steps are compared.
EFFECT: providing instrumental acoustic express evaluation of generators without removing them from a vehicle.
1 cl, 1 dwg
