EX540-NIST / Extech True RMS Industrial Multimeter/Datalogger, includes Traceable Certificate Datalog up to 9,999 readings with wireless USB interface capability to transmit readings to your PC in real time.
EX542-NIST / Extech Wireless True RMS Industrial MultiMeter Datalogger Real time data logging or transmit data wirelessly directly to PC - 30 feet / 10 meters.
EX570-NISTL / Extech True RMS CAT IV Industrial Multimeter with IR Thermometer, includes Traceable Certificate Built-in Non-contact InfraRed Thermometer with laser pointer.