MACS 609 Certification Practice Exam

Which item is not mentioned in the SAE J1991 standard of refrigerant purity?

1. Moisture

2. Oil

3. Acid

4. Particulates

The correct answer is: Acid

The correct answer pertains specifically to the components associated with refrigerant purity as outlined in the SAE J1991 standard. This standard focuses on the specifications necessary for the purity of refrigerants used in automotive and related systems. Moisture, oil, and particulates are all critical factors that can negatively impact the performance and longevity of refrigeration systems. Excess moisture can lead to corrosive reactions and freezing problems, oil contamination can affect the lubricating properties and functionality of the system, while particulates may cause blockages and wear in the components. On the other hand, while acids can be a concern in the context of refrigerant contamination and system integrity, they are not explicitly detailed within the SAE J1991 standard regarding the parameters for refrigerant purity. The standard primarily emphasizes the testing and acceptable limits for moisture, oil, and particulates, making acid the item that is not explicitly mentioned in this context. This underscores the standard's focus on direct physical contaminants that affect system performance rather than on products of chemical degradation or reactions that might occur.