This 4 Channel K Thermocouple SD Card Logger is the best tool for multiple measurements. It can record temperature changes by setting up data logging with no software required and no memory limit. It has 4-reading display with a backlight and real-time clock feature. The beeper and LED Alarm functions are programmable from the HIGH-LOW limit. The unit can be used by either wall-mount or handheld. Features: Super big LCD (104 x 47mm) Portable / wall-mount SD Card logger K-Type thermocouple Unlimited manual memories (depend on the SD card memory) Unlimited auto logging (depend on the SD card memory) HOLD function MAX/MIN value from power on Beeper and LED alarm One button press to display T1-T2 Display temperature change baseline Programmable temperature HIGH/LOW alarm limit Temperature offset function for adjustment purposes Over-range indication with error messages Blue backlight function 12 hour/24 hour time format selectable Real-time display (year-mon-date, hour-min) 20mins auto power off to save power Temperature units (°C/°F) selection Low battery indicator Specifications: Thermometer Main Unit Temp. Range : -200~1370°C (-328~2498°F) Resolution: 0.1°C,0.1°F Accuracy (under 18~28°C ambient temp.) : ±(0.3%rdg + 1°C) K Bead Type Thermocouple Temp. range: -50~200°C (-58~392°F) Sampling Rate : Programmable from 1 second up LCD Size (HxW): 47 x 104mm Operating Temp. : 0~50°C Operating RH% : Humidity