Testo 770 series true rms trms clamp meters testo 0590 7702 the testo 770 2 clamp meter is ideally suited for current measurement in switching cabinets it has a 956a range as well as an integrated temperature adapter for all type k thermocouples a unique feature of this meter is that one of the two pincer arms can be fully retracted into the instrument allowing individual cables to be easily selected the instrument detects direct and alternating current and can automatically select