OCR Text |
Show THE LAND SOLUTION The new Land Flamewatch Monitor has been developed to two criteria: i) A wider dynamic range to allow noisy oil and the very 'lazy' flames of a modern ultra Lo N O x burner to be monitored with one head. ii) Simplified operation and together with significant cost reduction In the Flamescan, filter selection was fixed at manufacture the signal processing, uses a digital programmable gain amplifier and this meant that noise was injected into the signal processing circuit as shown in the simplified circuit schematic in Fig.6. The new Flamewatch unit is a sophisticated analogue device allowing high gain amplification with minimal noise. It has a dynamic range 1.5 times greater than the Flamescan System and has the ability through the facility of its 'cut off function to move the flicker frequency 'window during optimisation on site. A schematic of the 'variable register' is shown in fig.7, this analogue device reduces the noise in comparison to the digital version. The system is a resistance divider where the output depends on the signal level, compensating more than adequately for the difference between signal levels in Lo N O x coal flames and the noisy oil flame. Fig 6 Fig 7 REF J; > 40ohms - 100Mohms JSH/22.8.97 7 |