Voltcraft ir 550a infrared thermometer with 8 1 measuring optics voltcraft ir 550a p the voltcraft ir 550a is an infrared thermometer for the contact free recording of temperatures in a range from 30 deg c to 550 deg c the ir 550a requires for display a standard multimeter with a millivolt dc measuring range the multimeter must have 4mm banana jacks and an input resistance of more than 1m omega the ir 550a has a target laser for accurate measurements p p the ir 550a requires a 9v bl