The apparatus is a device which may be placed inside a washing machine to verify that thermal disinfection has taken place by periodically sampling the temperature during a washing cycle. The results are automatically compared with local, regional, national or international standards for thermal disinfection. At the end of the washing cycle an indication is given that either thermal disinfection has taken place or that thermal disinfection has not taken place. The measurement, comparison and indication are independent of the temperature and time measurement parts of the washing machine and also independent of external human or mechanical or electronic computation and analysis. The device may be used in appliances such as laundry washing machines, automatic dishwashing machines or other washing machines.
