After several unsuccessful attempts with other USB SD card reader, I could by the Hama USB Micro SD Adapter successfully more Micro SD cards (2,8,16 and 32GB) via USB OTG on my Android Xperia Arc S mount. The other previously tried out Adapter for SD have drawn for my phone all too much power, so that it was impossible to mount. The adapter is nice and small, which I find very beneficial, I will, however, a loop or a keyring to attach the device to be able to secure from loss.
Now I can copy the pictures from my digital camera without a PC directly to my smartphone, which is traveling very beneficial. However, I can only use Micro SD card with adapter, instead of standard SD cards in the camera with this solution.
PS: Thanks to Prime the delivery took place the next day