Abstract: A measurement system for measuring a position of an eyebox of a virtual image of a pair of spectacles that can be worn on the head of a user can include a holding device for holding the spectacles at a predefined position, and a projection area element, onto which light beams that generate a virtual image can be projected via the first spectacle lens when the spectacles are held by the holding device. The projection area element is arranged at such a position in relation to the first spectacle lens that when the spectacles are held by the holding device, the position of the projection area element at least partially corresponds to the position of a pupil of the user when the user wears the spectacles on the head.

Abstract: A contact element suitable for SMD printed circuit boards is made of a flexible blank of sheet metal of approximate C-shaped cross-sectional configuration, with dimensions of a DIL package for SMD integrated circuits. The contact element is provided with bent terminals which are soldered onto respective bonding pads upon the circuit board while the top surface of the contact element is provided for contacting by a resilient external countercontact.

Abstract: An ionization fire detector of the type including a measuring chamber and a reference chamber having a common electrode which is connected to the gate terminal of a field-effect transistor by a profile piece of conductive caoutchouc having one end contacting the gate terminal and another end contacting the common electrode.