The number 1 reason for this error is the use of an incorrect probe.

The probes for TRED30-16R and TREL30-16 loggers are not interchangeable.

TRED30-16R loggers have a blue front label and are only compatible with the ST100 probes, which have a blue sleeve.

TREL30-16 loggers have a turquoise front label and are only compatible with the ST10 probes, which have a green sleeve.

For either logger, you must use the correct probe that is compatible with the logger, or the temperatures on the display and in the downloaded data will be incorrect.

If for some reason the color sleeve on the sensor has detached, you can identify if you have the correct probe with a simple test at room temperature. Correct and incorrect temperatures are shown below.

	TRED30-16R room temperature, approx 25 ºC	TREL30-16 room temperature, approx 25 ºC
ST100 probe	25 ºC	-30 ºC
ST10 probe	84 ºC	25 ºC