Abstract: The injector according to the invention serves for applying contrast media for X-ray and nuclear spin tomography and has a tube system (5) consisting of connection tubes (6) and a pump tube (7), as well as several storage vessels (4), each connected via one of the connection tubes (6) as well as a branching piece (8) to a pump tube (7) leading to a cannula. To each connection tube (6) a gas bubble detector (15) as well as a valve (11) are assigned, whereby further to the pump tube (7) a pumping organ (16) reversing the fluid flow from the storage vessel (4) to the cannula is assigned.

Abstract: A catalytic burner has a nozzle for forming a jet of combustible gas extending along a jet axis, a catalyst body supported offset from and immediately adjacent the axis heatable to an activation temperature at which it supports catalytic combustion, and a device like a piezoelectric crystal for igniting the jet and thereby forming at the axis a flame that heats the body. The flame is quenched after it has heated the body to its activation temperature.