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  1. I wished someone would give a detailed explanation of all the different scales on my gauges. Am I supposed to read the scale for R134A or do I ignore that and read the outer PSI only? I can’t find one blog or anyone that can give a detailed explanation. My gauge set came with no directions.

    1. Hope This will help you:

    2. Outer PSI Scale: This scale typically represents the pressure measurements in pounds per square inch (PSI). It is commonly used to measure the pressure of various gases, including refrigerants like R134A. When using your gauge set for general pressure measurements, you’ll rely on this scale.
    3. R134A Scale: The R134A scale is specific to the refrigerant R134A, which is commonly used in automotive air conditioning systems. This scale indicates the pressure of R134A refrigerant in the system. It is important to note that this scale is only applicable when working with R134A refrigerant. If you’re not working with R134A, you can ignore this scale.
    4. To interpret the gauge readings, you need to consider the specific refrigerant you’re working with and the pressure range you expect to see. Here’s a general guideline:

    5. If you’re working with R134A refrigerant, you should focus on the R134A scale. The pressure readings on this scale will give you an indication of the system’s pressure.
    6. If you’re working with a different refrigerant or measuring other gases, you should focus on the outer PSI scale. This scale will provide pressure readings applicable to a wide range of gases, including refrigerants other than R134A.