An apparatus for measuring the magnetic field distribution of a magnetic sample includes a magnetic field sensor arrangement having three, orthogonally-disposed, Hall sensors for sensing the magnetic field produced by a magnetic sample at a given location, The sensor arrangement is scanned along a predetermined scan pattern. The trigger assembly includes a trigger, a sear, a sear activator and a connecting cable. A gas flow is passed over the substrate to deposit the dielectric film. A predefined modification criteria is stored. The screw can provide stability and compression to the joint. In particular, the invention discloses certain indole derivatives and their function as inhibitors of monocyte chemoattractant protein-1 and RANTES induced chemotaxis.