A temperature-compensated rectifying component is configured to receive an input signal and comprises: a diode part, for rectifying the received input signal and providing a rectified output signal thereby, the diode part having an operational temperature; and a temperature compensation controller, configured to control a power dissipated by the diode part over a predetermined period of time, such that an average of the operational temperature over the predetermined period of time meets pre-set criteria. This may be used in a RF detector for generating a DC level from a RF input signal, which may form part of a control circuit for setting an amplitude of an RF potential for supplying to an electronic amplifier in an analytical instrument, such as an ion optical device.