A method for producing tetrafluoroterephthalic acid difluoride comprising reacting tetrachloroterephthalic acid dichloride with potassium fluoride in the presence of dimethyl sulfone. When operatively interconnected, and in its raised resting position, the device forms what is substantially a forward leaning parallelogram bisected by the consolidated length of a slide and slide-guide, which forms two substantially congruent triangles sharing a common side. The described system has multiple paths in the synchronization circuitry that allows responses from several devices under test to be synchronized with each other so that parallel testing is supported.