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Bovar 900 SO2 analyzer Ametek/Western Research Get Quote



The Western Research 921M SO2 Analyzer performs simultaneous dual range analysis on a continuous basis. It has a sealed gas reference cell for increased stability and accuracy.The Model 921M is suited for lower range uses (i.e. 0-50ppm and lower). The Model 9000RM can be configured to measure most gas species that absorb in the UV (examples NOx, H2S and SO2). The optional low range white cell provides longer path length for measuring lower concentrations. For example, the minimum full scale for SO2 is 25 ppm, with an accuracy of 1% of full scale. of both methane and non-methane hydrocarbons (NMHCs).

Key Features

  • Very Stable
  • Simultaneous dual range analysis
  • Ranges- 0-100 to 0-5000 ppm
  • Excellent for Low PPM Ranges


  • Simultaneous dual range analysis
  • Ranges- 0-100 to 0-5000 ppm
  • Excellent for Low PPM Ranges
  • Very Stable

Technical Specifications

Custom Ranges (9000) Standard: 0-25 Low to 20000PPM Hogh
Zero Noise (9000) Standard: .1 PPM RMS (300 second avg time)
Communications (9000) Modbus RTU RS485 and Modbus TCP Fast Ethernet - network connection or web-based server
Zero Drift (24 Hour) (9000) Typically better than 2% full scale standard ranges in 24 hours
Span Drift (9000) Standard: <.5% reading-24 hrs <1% reading-7days High Level <2% reading-7days
Outputs (9000) Two (expandable to six) isolated Analog Outputs, each configurable to 0-20 mA, 4-20 mA, 0-5V DC
Detection Method (921) Dual wavelength; Nondispersive UV
Selectable Ranges (921) 0-100 to 0-5000 ppm full scale; user selectable
Power Requirements (921) 120 V; 60 Hz
Detection Limit (921) 0.25 ppm
Selectable Outputs (921) 1V, 10V, 0-100mA, 4-20mA; RS-232 port
Ambient Conditions (921) 5° to 50°C (41° to 122°F); 5 to 95% relative humidity, non-condensing
Zero Drift (921) Less than 0.5 ppm in 24 hours (for SO2 only)


  US Metric
Dimensions 7 x 19 x 23.5 in. 180 x 480 x 600 mm


  US Metric
Weight 27 lbs 12.3 kg