The Energy Audit IR Thermometer/Scanner with Star Burst Laser Targeting, No. IRTC50, from General Tools & Instruments, allows users to designate a set point and determine whether subsequent readings are within or outside selectable ranges from that set point. A set-point reference temperature is first acquired and stored, then the user selects one of three reference ranges (+/-1 degrees F, 5 degrees F or 10 degrees F). This tool features a large backlit LCD display and is powered by a single 9V battery The instrument has a measurement range of -40 degrees to 428 degrees F.