Patent ID: 8271230

Claim:
A method for monitoring a thermoelectric heating and cooling device of a system for cycling liquid reaction mixtures through a series of temperature excursions, comprising: applying a first quantity comprising one of an electric current (I) and an electric voltage (U) to said thermoelectric heating and cooling device of said system for cycling liquid reaction mixtures through a series of temperature excursions and measuring a second quantity comprising one of temperature and the other one of the electric current (I) and the electric voltage (U) to obtain a first test value; applying the first quantity to at least another thermoelectric heating and cooling device and measuring the second quantity to obtain a second test value; determining a monitoring value on basis of a comparison of said first and second test values; comparing said monitoring value with at least one predefined threshold value for said monitoring value to obtain a monitoring result indicating a probability of failure of the thermoelectric heating and cooling device.