Identification of defective compressor using acoustic signals

Compressor is one of the main parts in the refrigerator having a critical role in the proper circulation of the refrigerant in the vapour compression cycle. Quality inspection techniques are regulated and carried out in the manufacturing stage to check the quality of the compressors. A considerable quantity of defective compressors results in economical loss and therefore, there is a need for an advanced technique for the early identification of defective compressors. It is noted that the sound appears to have fluctuations when the compressors are malfunctioning during the service period or early stage. This motivated to further perform research using control charts in the early manufacturing stage and to come up with a novel statistical-based technique for assessing the quality of refrigerator compressors based on acoustic data. The study revealed that the sample points in the control chart exceeded the upper control limits in I chart and MR chart when the noise is produced. The process capability indices are less than one indicating the defected compressors. The research is promising as an alternative method for assessing the quality inspection techniques.