- DynamicOpacity™ Ratiometric Opacity instruments are often used to replace Opacity instruments which typically require extensive maintenance and servicing. As the instrument is measuring the ratio of signal scintillation to absolute light intensity, the PCME STACK 602 continues to operate with lens contamination of up to 90%. This is because both the reduction in light intensity and the variation in intensity caused by lens contamination are affected by the same proportion, resulting in no net effect. In contrast with traditional Opacity measurement, the DynamicOpacity™ Ratiometric Opacity method also compensates for potential misalignment or aging of the light source.
- Air purge should be connected to the transmitter and receiver heads to provide a positive displacement of air away from the lens surfaces, however since air usage is in the order of 30-60 litres/minute it is economical to use plant instrument air rather than install dedicated air blower systems.
- The PCME STACK 602 includes automated electronic Zero and Span checks which monitor instrument integrity. These checks simulate the operation of the instrument and permit any internal instrument problems to be self-detected. Span checks for the CEM are implemented automatically and are performed by varying the light intensity in the transmitter head. The zero check involves measuring the variation with no transmitter light present. These checks are carried out automatically every 3 hours.
- DynamicOpacity™ Ratiometric Opacity instruments use a diffused transmitter which emits light at a range of angles from the transmitter source. Combined with the ratiometric measurement algorithm this means that the alignment of transmitter and receiver are less critical than with traditional Opacity instruments, and consequently do not require elaborate alignment procedures during installation.
- Additionally, the transmitter and receiver heads are designed so that the lenses can be accessed and cleaned without the need for disconnecting flanges from the stack, ensuring correct alignment even after maintenance intervention.