How can the volume of refrigerant in a recovery cylinder be determined if the volume is unknown?

To determine the volume of refrigerant in a recovery cylinder when the volume is unknown, the method involving weighing the cylinder is effective and precise. When you weigh the cylinder after it has been filled with refrigerant, you can calculate the amount of refrigerant present by taking a measurement of its current weight and subtracting the tare weight, which is the weight of the empty cylinder.

This calculation provides the net weight of the refrigerant contained within the cylinder. By knowing the refrigerant type and its specific density, you can convert this weight into a specific volume. This method is particularly reliable because it considers the actual refrigerant loaded into the cylinder rather than estimating based on dimensions or pressure, which can be less accurate due to varying refrigerant states and the characteristics of the liquid and vapor phases.

Measuring internal diameter or using a pressure gauge may not yield an accurate volume calculation, as the refrigerant may not be entirely in liquid form depending on temperature and pressure conditions, leading to misleading volume assessments. Hence, the most direct and reliable approach remains the weighing method combined with tare weight subtraction.