The present invention relates to a composition suitable for use in an ECL assay wherein electromagnetic radiation emitted by the composition is detected. At least two tips are situated at an axial distance from each another, on at least two blocks on an arm of the robot manipulator. The built-in circuit comprises data generating means for generating a test data byte and serializing means coupled to the data generating means for converting the test data byte into serial test data. These signals are notionally split in equal spacings in the range covered by each node, each notional signal being shown with vertical tally sticks. The pivot may also be on the longitudinal access of a pole to which wind gathering means, such as flags or banners may be attached.