What must recovery devices be capable of achieving in terms of vacuum measurement?

Recovery devices must be capable of achieving a 4 inch vacuum. This requirement is critical to ensure that as much refrigerant as possible is removed from a system to minimize environmental impact and enhance system efficiency. In the context of refrigerant recovery and recycling, achieving a vacuum of 4 inches of mercury (inHg) indicates that the recovery device can adequately remove remaining refrigerant and reduce the pressure within the system to an acceptable level.

The 4 inch vacuum standard is designed to ensure that the majority of the refrigerant is removed, helping to prevent refrigerant leaks into the atmosphere. This is particularly important considering the environmental implications associated with refrigerants, which can be potent greenhouse gases. Understanding the capacity of recovery devices in terms of their ability to reach specific vacuum levels is essential knowledge for technicians handling refrigerants in any capacity, as it speaks directly to compliance with environmental regulations and the effective management of refrigerant recovery practices.

The other options represent lower vacuum measurements that would not meet the industry standards necessary for efficient recovery and environmental protection.