A method of controlling synchronous running of a plurality of electronically commutated motors, each of which includes a stator having a stator winding, a permanent-magnet rotor, and at least one arrangement, associated with the respective motor, for sensing its rotor position and for generating a rotor position signal. The grate adapter unit is trimmed, either at the factory, at the contractor’s facilities or at the installation site, at the desired location to select a desired one of the mounting flanges that is appropriate for the collection grate to which the grate adapter is being fit. A roll awning is attached to the awning frame. In the common focal plane, an assembly of several matrix detectors are arranged and oriented on the superimposition zone of the image fields of the telescopes in the wavefront. Removed material from the first surface is monitored to detect fluctuations in a variable of composition in the layer, and removal of material from the first surface is terminated when the composition of monitored material meets a predetermined criterion. A plunger rod is secured to the plunger and extends outward from the container through the bottom cap.