Extech ex205tex210t digital multimeters with optional ir thermometer function extech ex210t the extech ex210t digital multimeter is an auto ranging true rms meter providing a more accurate reading when measuring distorted waveforms it measures acdc voltage and current resistance continuity audible and has a diode test function the ex210t also incorporates a patented built in ir thermometer with laser pointer for locating hot spots with 41 distance to target ratio supplied with test