This device is not a safety feature. The sample protection thermostat can be set to be a few degrees above the bath set temperature.
In the unlikely event of failure of the primary temperature control system, the sample protection thermostat will maintain the water in the bath at a temperature a few degrees above the control temperature. This will be indicated by the two orange lamps cycling on and off. If this happens, first check that the sample protection thermostat is not set to a lower temperature than the primary control system. If that is not the reason, the main control thermostat is not operating correctly. The bath can continue to be used without compromising the safety of persons or the surroundings until current work is completed. However, it is recommended to have the bath checked by a competent person as soon as conveniently possible.