Machine Fault Diagnosis - Introduction to CEM Noise Meter
Modern industrial production cannot do without machines, and the application of machines to engines often produces various types of noise. In the current era of advocating environmentally friendly production, using noise meters for noise control has become one of the necessary methods for noise control.
For the selection of noise meters, it is necessary to distinguish. Different types of noise meters should be used for measuring different environments. Guangzhou Hongcheng has launched a series of professional noise meters, such as the DT-85A noise meter, which is suitable for measuring the noise in residential areas, schools, and home environments; The noise meter DT-815 is particularly suitable for measuring mechanical industrial noise, etc. Its series of noise meters can be widely used in various noise engineering, quality control, health prevention and various environmental sound measurement applications, such as residential areas, industrial and mining areas, schools, airports, and other occasions.
Mechanical production carries out noise control. When diagnosing faults caused by excessive engine noise, a noise meter can be used for first troubleshooting, such as those generated by air compressors and power take-off. Do not mistake these noises for engine noise, and remove the accessory drive belt to eliminate the noise caused by these devices. Noise can also spread to metal parts that are not already problematic, so using a noise meter and stethoscope will help determine the location of motive noise.
Handheld portable noise meters reach various measurement positions, and if the noise heard changes with the crankshaft speed (engine speed), it may be related to the crankshaft, connecting rod, piston, and piston pin. According to the changes in noise data on the noise meter, if the noise changes with the camshaft speed (half speed of the engine), it may be related to valve transmission components. A handheld digital noise meter can help determine whether the noise is related to components running at the speed of the crankshaft or camshaft.
Components and accessories driven by the engine, such as gear driven fan clutches, hydraulic pumps, belt driven chargers, air conditioning compressors, and turbochargers, may all contribute to engine noise. Using a noise meter as an aid, the following information can be used to guide the diagnosis of engine noise:
Main bearing noise: The knocking noise generated by loose main bearings can be heard when the engine is under load, and its noise is loud and dull. When the engine is dragging or driving under heavy load, this noise is the loudest and the knocking sound is more dull than the noise generated by the connecting rod. Using Guangzhou Hongcheng's noise meter DT-8852 for measurement, it can select A and C gears, measure low audio noise using A gear, measure high-frequency noise using C gear, and store data for easy connection to computers for analysis and noise source investigation.
