Erste Ergebnisse der Erprobung des photometrischen Zwillingsreflektors

First measurements of the short time variations of Ap stars with the twin telescope show a nonlinear drift caused by a sensibility of the amplifier depending on temperature. Moreover we found a dependence of the impulse rate on the position of the star image in the diaphragm. Special test measurements with a simple incandescent lamp show that this telescope gives results with an accuracy of ± 0.002 mag after elimination of these effects.