The LogTag data loggers have a start/clear/stop button that needs to be pressed firmly with thumb or finger to make the screen display "starting". This will blink several times until it "double blinks". When "starting" blinks twice rapidly instead of once, take your finger/thumb off the button. The logger display should produce a temperature; this is how you know it is started.
This number indicates the LogTag took a reading with the probe not inserted. The display will change when the next sample is taken and the probe is inserted properly.
This indicates that the logTag either ran out of memory and stopped recording, or was stopped by holding the start/clear/stop button. To restart the readings, insert the LogTag into the docking station and run it through the software again.
The top button on the front of the logger says "review/mark"; press this button to review the min/max for the previous days. The numbered box below the temperature indicates how many days prior to the current reading that min/max was taken.
The "X" over the battery symbol indicates a dead battery.
There is a white plastic square that is adhered onto the back of the LogTag that may be covered by a calibration sticker. If you peel the calibration sticker up slightly from the bottom left corner you will see a notch that you can slide a fingernail or razor underneath to pry up the white square. Underneath the square is a round plug that you must twist (best to use a spare battery or quarter) to the left to remove and reveal the CR2032 battery. This can be removed with a small standard (flat) screwdriver.
*Each kit comes with a spare battery; check your original box before ordering a new bettery.