Textbook Problem

Which of the following statements about manifold gauge sets is not true?

1. An adapter is required for using R-12 gauges on an R-134a system.

A manifold gauge set is used when discharging, charging, and evacuating and for diagnosing trouble in an A/C system.

The gauge manifold is designed to control refrigerant flow. When the manifold test set is connected into the system, pressure is registered on both gauges at all times.

R-134a service hoses have a black stripe along their length, the low-pressure hose is blue, and the high-pressure hose is red.