A/C Electronic Scales are used to ensure you have a properly charged a/c system. When servicing R134a ac systems, it is necessary to ensure an accurate refrigerant charge. Unlike R12 systems, R134a a/c systems are sensiitve to being over or under charged. +/- 2 oz. can greatly affect the performance of the system.
Thermometers are used to measure the vent temperature.
A/C Electronic Scales are used to ensure you have a properly charged a/c system. When servicing R134a ac systems, it is necessary to ensure an accurate refrigerant charge. Unlike R12 systems, R134a a/c systems are sensiitve to being over or under charged. +/- 2 oz. can greatly affect the performance of the system. 
