A PIM test bench including a first duplexer, having a first port connected via a first filter to a third port and a second port connected via a second filter to the third port. The first port is fed by signal sources providing RF signals at first and second frequencies. A spectrum analyzer is connected to the second port. A device under test is connected between said third port and a third port of a second duplexer. Each of the first and second ports of the second duplexer is connected to a PIM optimized load and/or a standard load. The second duplexer is preferably identical to the first duplexer. For minimizing self-intermodulation, at least the first duplexer comprises at least one filter component and a metal housing. The housing further includes a monolithic metal body and a metal cover capacitively coupled to the body without any galvanic contact.