ML9850A  ML9850B  ML9850H

The Monitor Labs ML9850 SO2 A/B/H SO2 analyzer utilizes UV fluorescence method for measuring sulfur dioxide in air. A UV lamp coupled with a bandpass filter generates the peak wavelength at which maximum fluorescence of SO2 occurs. Range of the ML9850A/B is 0-20 ppm with the ML9850H featuring a range of 0-400 ppm capable of 0-4000ppb with a 10:1 dilution of the sample air.

The ML 9850 features an option of an internal or external sample pump. Typical operational time of these internal pumps is expected to be between 3-5 years before any maintenance is required. In some cases  you can extend the life of the pump through flipping the carbon vanes on the pump. This should be considered only a temporary fix, designed to maintain instrument operation until the pump can be serviced or replaced. External pump versions use critical orifices to maintain sample flow.  Any action should be done in consultation with a professional air monitoring equipment company.

Typical consumables with the ML9850 include background scrubbing media, in-line filter for the background scrubber, dessicant for the PMT, and UV Lamps. UV lamps have a typical lifespan of between 6 months and 3 years, and the lamp peak should be checked on an annual basis with an oscilloscope. Annual maintenance of the ML9850 includes cleaning of the measurement cell and optical filters, servicing of the PMT, and replacement of the o-rings in the measurement cell. Annual service kits for the ML9850 are available and include all materials (e.g. o-rings, sintered filters, and desiccant) along with directions for completing the service.