Abstract: A titration apparatus, which operated volumetrically and/or coulometrically, includes a basic apparatus with a control and actuation arrangement for the volumetric metering of reagents, a metering unit for the volumetric titration removably attached to the basic apparatus, and mechanical coupling elements for connecting the metering unit to the actuation device. Instead of the volumetric unit or in addition thereto, a coulometric titration cell may be connected with the basic apparatus directly or by an adapter unit, while using the same control device as the metering unit.