Adaptor for holding printed-circuit boards which are to be tested on both sides

In order to simplify the reequipment and construction of an adaptor for testing printed-circuit boards on both sides by means of an automatic measurement system, the contact-carrier boards which can be displaced towards one another and carry on their inside the contact needles which can be pressed onto the top of the printed-circuit boards which are to be tested, together with the holding device (which is provided between these contact-carrier boards) for the printed-circuit board are constructed as a replaceable adapter unit on whose rear side the contacts which can be connected to the measurement system are fitted, while the drive unit which has the drive device for displacing the contact-carrier boards is fitted to the measurement system and has two compression arms which can be displaced towards one another, between which the replaceable adapter unit can be inserted.