PG-235/250 Portable Emissions Analyzers The Model PG-235/250 is a compact, light weight portable instrument. The EPA-ETV tested Model PG-250 instrument has the capability to simultaneously analyze NOx, CO, CO2, O2, and SO2 while the PG-235 can be used to monitor NOx, CO and O2. Unlike other multi-gas analyzers that utilize electrochemical cells, the PG-235 and PG-250 instruments employ proven and acceptable technologies for gas measurements. Both instruments have a built-in sample conditioner that includes a thermal-electric cooler, filters, and sample pump. All that is required to operate the analyzer is a 110 V ac power source. Both instruments are ideal for stack testing or taking periodic measurements from process streams. The analyzers can even be used as a temporary back-up system for a continuous emissions monitoring system (CEMS) should the primary system fail or require shutdown for maintenance. The PG-235/250 instruments are available with optional zirconium oxide sensors for O2 measurements. Competitively priced, the PG-235/250 offers cost-effective solutions whenever multi-gas analyses are required. When compared with multiple purchases of single measurement analyzers, the PG-235/250 offer remarkable savings.