A profiler or scanning probe microscope may be scanned across a sample surface with a distance between them controlled to allow the sensing tip to contact the surface intermittently in order to find and measure features of interest. The LTC generator comprises a rising edge detector that is adapted to detect a frame sync input corresponding to a beginning of a frame time of video data and to generate a first synchronization signal corresponding to the frame sync input and a frame length measurement block that is adapted to count a number of clock cycles in the frame time. Thus, the monitor request instruction issuing unit, the monitor data obtaining unit, and the monitoring application executing-section can operate mutually asynchronously. The engine coolant passage opens into, and is fluidly connected to, the mounting bore to cause coolant in the coolant passage to contact the annular outer surface of the nozzle assembly. The pin includes an abutment movable to a locked configuration in the second portion of the opening, wherein the abutment defines a cross-sectional dimension greater than that of the first portion of the opening. 6, and provided that the sum of 1)+2)+3) is 1.