Abstract: A multi-wavelength light source device includes three light source devices. The light source device includes a plurality of light emitting elements, and a dispersing section making wavelengths of light beams emitted from the respective light emitting elements different from each other, a spectral line width of the emitted light beam in each of the light source devices is equal to or greater than 0.2 nm, a wavelength of the red light beam in the light source device for emitting the red light beam is greater than 612 nm, a wavelength of the green light beam in the light source device for emitting the green light beam is greater than 525 nm and smaller than 538 nm, and a wavelength of the blue light beam in the light source device for emitting the blue light beam is greater than 465 nm and smaller than 468 nm.

Abstract: Connection and disconnection between an apparatus and an electric wire are made by fitting an electric wire side housing in an apparatus side housing inside a mounting hole or removing the electric wire side housing from the apparatus side housing, so that the need for time-consuming work for tightening or loosening a bolt or work for attaching a cover to a terminal block or detaching the cover from the terminal block as is conventional is eliminated and workability is good. In addition, the apparatus side housing can be fixed into the mounting hole by a stopper and a retainer, so that workability is good as compared with the case of fixing the apparatus side housing by bolt tightening.

Abstract: A method of production of a dielectric ceramic composition having at least a main component of Ba2TiO3, a second subcomponent including at least one compound selected from SiO2, MO (where M is at least one element selected from Ba, Ca, Sr, and Mg), Li2O, and B2O3, and other subcomponents, comprising the step of: mixing in said main component at least part of other subcomponents except for said second subcomponent to prepare a pre-calcination powder, calcining the pre-calcination powder to prepare a calcined powder, and mixing at least said second subcomponent in said calcined powder to obtain the dielectric ceramic composition having molar ratios of the subcomponents to the main component of predetermined ratios. As the other subcomponents, there is a third subcomponent including at least one compound selected from V2O5, MoO3, and WO3. A ratio of the third subcomponent to 100 moles of the main component is preferably 0.01 to 0.1 mole.