Abstract: In an optical signal generating apparatus of this invention, output light from a light source driven by a light source driver is externally output from an optical receptacle through a variable optical attenuator. An output monitor unit can be detachably connected to the optical receptacle through an optical connector. When an absolute level of the output light is to be set, a CPU compares a set value from an output level setting unit with an output value from the output monitor unit and controls the variable optical attenuator and the light source driver so that a comparison error becomes zero. The CPU maintains the above control of the variable optical adjuster and the light source driver so that the light is output to be the desired level set by the output level setting unit even after the output monitor unit is disconnected from the optical receptacle including the timing at which the comparison error becomes zero.

Abstract: A radio wave power measuring apparatus is disclosed, which includes a thel load confined in a reference temperature housing, a wave absorber disposed in the load for absorbing radio waves supplied thereto, a heater for heating the load, a thermoelectric cooler element provided between the housing and the load for the load, a temperature difference detector having a thermoelectric sensor element provided between the housing and the load for detecting the difference in temperature between the housing and the load, a heater controller for feeding to the heater the power corresponding to the temperature difference detected by the detector so as to maintain the load and the housing at the same temperature, and a measuring member for measuring the power fed to the heater.