Voltcraft pm 37 usb power meter voltcraft pm 37 p the voltcraft pm 37 is a digital hand multimeter that enables a quick and easy measurement of the interface voltage and the current consumption of the connected usb device p p the power meter is simply inserted between the usb interface of one device and the usb port of the other device p p the display switches between voltage and current display the power meter can be applied to any usb port the data lines are unaffected p voltcr