Fieldpiece SC640 Digital Clamp Meter Loaded Series TRMS is a digital clamp meter that is versatile, durable and features all of the measurement options that HVACR technicians need. Fieldpiece SC640 features TRMS AC/DC voltage measurement and AC amp measurement, as well as non-contact voltage measurement and much more. The new swivel head design adds flexibility to the meter and ease of access to any wire or cable.