Abstract: One aspect of the invention provides an electric heater including: a resistive heating element; a current transformer positioned around a portion of the resistive heating element or a lead thereto, the current transformer adapted and configured to produce a secondary induced current proportional to a primary current flowing through the resistive heating element; and a controller communicatively coupled to the resistive heating element and the current transformer. The controller is programmed to either: (i): detect a deviation between the secondary induced current and a reference value; and in response to the deviation, generate an alert; or (ii) communicate to a remote server programmed to detect a deviation between the secondary induced current and a reference value.

Abstract: A heater with an optical sensor for over-temperature protection. The heater includes a heating element and a sensor assembly including a coupler and an optical sensor. Wavelengths emanating from the heating element passes directly through the coupler to the optical sensor. The optical sensor provides an over-temperature feedback signal for limiting power to the heating element to avoid an over-temperature condition for the heating element.

Abstract: A heater with an optical sensor for over-temperature protection. The heater includes a heating element and a sensor assembly including a coupler and an optical sensor. Wavelengths emanating from the heating element passes directly through the coupler to the optical sensor. The optical sensor provides an over-temperature feedback signal for limiting power to the heating element to avoid an over-temperature condition for the heating element.