The invention relates to an electric
frost prevention observation window, comprising an observation window, a
heating film adhered on the inner surface of the observation window, a
flange, a sealing ring and a heating
control circuit; wherein the observation window is arranged on wall body by the
flange and sealing ring, the heating
control circuit comprises a
temperature sensing device, a temperature judgement control device and a
relay, and the temperature judgement control device presets a standard
voltage corresponding to critical temperature of
frost prevention; the
temperature sensing device acquires actual temperature of the
heating film and converts the actual temperature into corresponding
voltage signal, and the
voltage signal is transmitted to the temperature judgement control device; when the actual temperature is lower than the critical temperature, the temperature judgement control device causes the
relay to be closed, the heating
control circuit and the
heating film form a close circuit, and the heating film is heated; when the actual temperature is higher than the critical temperature, the
relay is released, and the heating control circuit and the heating film form an open circuit. The invention has good sealing effect, can effectively avoid
frost formation and
dew formation and can be widely applied to related fields such as environment
simulation laboratory and
climate simulation laboratory.