• Compared to other Opacity systems, PCME’s PS-1 compliant instrument has lower long term zero drift, meaning that it can be used to monitor dust levels as low as 10mg/m³ in a 5m stack without suffering from zero drift which causes errors when calibrating an instrument.
• The Opacity and DynamicOpacity™ measurement algorithms can be combined in certain instruments to provide a more reliable solution for dust measurement than pure opacity system.

PCME’s Double Pass Opacity instruments are available with a range of quality assurance features as required by US EPA PS-1 standards:

• Automatic Opacity zero check which challenges the full operation of the transceiver by measuring the signal when a mirror is automatically inserted into the beam after the final lens.
• Automatic span checks, to check ability of the instrument to correctly measure attenuation caused by an optical filter inserted ahead of the zero mirror.
• Audit filters which may be manually inserted into instrument for zero and linearity checks.