A fluid bed apparatus module comprises an outer wall enclosing a processing chamber and has a lower flange connection and an upper flange connection, the lower flange connection being adapted to connection with a flange connection of a supply of fluidising gas, and the upper flange connection being adapted to connection with a flange connection of a filter chamber for gas discharge. The range of memory has first and second opposite ends. , falling within the range of 23\xb14\xb0 C. The timing signals are generated based on a common system clock and cause the deflectors to scan the spots and the detection channels to generate a detected image at a synchronized timing so as to minimize jitter between the scan portions in the response image.