Model 43i-HL High Level SO2 Analyzer

Measure high levels of SO2 from a source up to 10,000 ppm with the Thermo Scientific™ Model 43i-HL SO2 Analyzer, the first gas analyzer to utilize pulsed fluorescence technology to measure SO2.

Discover the iQ to work smarter with our next-generation 43iQ High-Level Sulfur Dioxide Analyzer.

Key Features:

  • Measures up to 10,000 ppm in an extended range
  • Standard dual range and auto ranges
  • Temperature and pressure correction
  • User-selectable alarm levels for concentration

iSeries Advantage:

  • Ethernet connectivity for efficient remote access
  • Enhanced user interface with one-button programming and large display screen
  • Flash memory for increased data storage and user-downloadable software
  • Enhanced electronics design optimizes product commonality
  • Improved layout for easier accessibility to components



Detectable AnalytesSulfur Dioxide
Detection Limits0.5 ppm
Flow Rate0.6 to 1.0 L/min.
Inputs16 Digital Inputs (Standard), 8 0 to 10 VDC Analog Inputs (Optional)
Linearity±1% full scale
Response Time80 sec. (10 sec. averaging time)
Span Drift±1% full scale
Temperature (Metric) Operating20°C to 30°C
Zero Noise0.25 ppm
Certifications/ComplianceETL, CSA, UL, CE, UKCA
Depth (English)23 in.
Depth (Metric)584 mm
DescriptionHigh Level SO2 Analyzer
Height (English)8.62 in.
Height (Metric)219 mm
Measurement RangeStandard Ranges: 0-10, 20, 50, 100, 200, 500 and 1000ppm 0-20, 50, 100, 200, 500, 1000 and 2000mg/m3 Extended Ranges: 0-100, 200, 500, 1000, 2000, 5000 and 10000ppm 0-200, 500, 1000, 2000, 5000, 10000 and 20000mg/m3 Custom Ranges: 0-10 to 1000ppm (standard), 0-100 to 10,000ppm (extended) 0-20 to 2000mg/m3 (standard), 0-200 to 20,000mg/m3 (extended)
Mounting OptionsBench mounting (standard), EIA, Retrofit
OutputsSelectable voltage, RS232/RS485, TCP/IP, 10 status relays, and power fail indication (standard). 0 to 20 or 4 to 20mA isolated current output (optional)
Voltage100/115/220/240 V
Weight (English)55 lb.
Weight (Metric)25 kg
Width (English)16.75 in.
Width (Metric)425.45 mm
Zero Drift<1ppm/day
Unit SizeEach