Martindale cm87 2000a ac dc true rms clamp multimeter martindale cm87 p the martindale cm87 is a high specification true rms clamp meter packed full of functions for the installation testing and maintenance of domestic and industrial installations p p this robust clamp meter provides true rms measurement of ac current up to 1500a and ac voltage to 750v it will also measure dc current to 2000a and dc voltage to 1000v the cm87 has the added benefit of temperature measurement between 20