to this layer fig2 30 illustrate various concrete embodiment forms of a testing device to detect the emission of the printed el picture 29 the testing device according to fig2 24 consist essentially of the two opposing supports 28 30 between which an alternating electromagnetic field exists in the intervening space on one side of these two supports 28 30 is a housing 49 that has a switch 50 on top of it and which houses corresponding batteries 46 to provide current it also houses an electronic circuit board 47 containing the electronics 48 by pressing the switch 50 the alternating electromagnetic field is produced that at least partially penetrates the printed el picture 29 that is designed as a security feature 9 10 fig6 amp 7 thus causing it to illuminate fig2 shows that the previously described electrode arrangement 35 can be located either on the inside of the lower support 30 or on the inside of the upper support 28 fig2 and 26 show that the electrode fingers 39 40 are separated at a distance from one another and form parallel field gaps 26 between them the entire arrangement is then connected to contacts 34 using conducting contact surfaces 52 applied for this purpose in addition another luminescent layer 51 can be arranged on the inside of the support 28 the function of this luminescent layer was already explained with respect to fig2 in contrast to the previously described finger like meshing electrodes fig2 and 28 describe electrodes 53 54 that are also arranged opposite one another and are contacted using corresponding connectors 31 in addition according.