The measurement of the Schwarzschild exponent of Ilford Q2 plates by mass spectrography with secondary ion emission

The Schwarzschild exponent was measured over a large range of exposure times between 0.05 and 1920 sec for Ilford Q2 plates which are activated by ions of 20keV (mass 40 to 48) and which are developed at 22 C by the Multiplex Guilleminot developer. Under these test conditions, the Schwarzschild exponent was found to be almost equal to 1 and the reciprocity law is valid for the plates used.