Gastech

Sampling from combustion sources is often challenging due to the presence of volatile material. Volatile components are extremely sensitive to sampling conditions and can grow existing particles and form new particles through condensation.

By evaporating and oxidizing volatile particles, the NPET 3795 measures only the remaining solid particles. The NPET 3795 fully meets Swiss Regulation 941.242 for the periodic certification of diesel-powered machinery equipped with a DPF. Not only is it a rugged, mobile and a cost effective instrument, but it also comes with a software package optimized for Microsoft Windows 8 tablet allowing for ease of use in laboratory and field testing applications of on and off road equipment. A sophisticated instrument in a simple package, the NPET 3795 combines a traditionally complex system of components into a portable, robust measurement tool.

The five key design components include:

• Sampling Probe: A stainless steel sample probe with built-in diluter and removable clamp allows for easy measurement of high concentration particle number emissions directly from the tailpipe.
• Preconditioner: a 1.0μm cyclone removes large particles while a water trap removes water droplets from the exhaust gas sample.
• Recirculating dilution flow conditioner: A silica desiccant dryer and two high capacity HEPA filters efficiently dry and clean the recirculating dilution flow for continuous operation with no loss of accuracy.
• Volatile particle remover: a catalytic stripper heated to 350°C evaporates, and oxidizes volatile components to remove them from the sample stream.
• Particle counter: An isopropanol-based CPC provides accurate, direct measurement of particle number emissions at high and low concentrations over the entire range of temperature and altitude conditions.