43iQ Sulfur Dioxide Analyzer

Get 24/7 access to your analyzer’s information with a Thermo Scientific™ iQ Series Gas Analyzer. The iQ Series Gas Analyzers are engineered to get smarter over time and help minimize troubleshooting time with a highly precise, yet tough solution. The Thermo Scientific™43iQ Sulfur Dioxide Analyzer provides the same level of performance when measuring sulfur dioxide (SO2) in ambient air up to 100ppm using pulsed fluorescence technology.

Discover the non-stop intelligence of the iQ Series Gas Analyzer now with a two-year warranty.  Our next generation platform of gas analyzers includes:

Predictive Diagnostics

Address problems before they occur with improved serviceability and plug-and-play components. 24/7 access to your analyzer’s information helps minimize troubleshooting time with innovative,  interchangeable DMC modules in a highly precise, yet tough solution.

Proactive Communications

Maintain optimum performance through iQ360 and email alerts. When subscribed to iQ360 service, your instrument communicates directly to our technical support team upon alarm activation. Our technical support team develops a corrective plan and emails it to your staff. Eliminate surprises and take control of your day with the iQ Series Gas Analyzers.

Personal Device Connectivity

Real-time, continuous remote monitoring is now possible with the iQ companion mobile device app. The iQ app allows for remote monitoring of iQ gas analyzers, simplified ways of getting in touch with us, and instant access to both maintenance alerts and product documentation.



Detectable AnalytesSulfur Dioxide
Flow Rate0.5 L/min. (standard)
Inputs4 Isolated Voltage Inputs 0 to 10 V, 16 Digital Inputs (TTL)
Linearity±1% full scale
Response Time60 sec. (10 sec. average time), 110 sec. (60 sec. average time), 320 sec. (300 sec. average time)
Span Drift±0.5% full scale (24 hr.)
Temperature (English) Operating32°F to 113°F
Temperature (Metric) Operating0°C to 45°C
Zero Noise1.0 ppb RMS (10 sec. averaging time), 0.5 ppb RMS (60 sec. averaging time),0.25 ppb RMS (300 sec. averaging time)
Certifications/ComplianceCE, TUV-SUD Safety, US EPA: EQSA-0486-060, UKCA
Communication PortsSerial ports:
1 RS-232/485 port
1 RS-485 external accessory port
Other ports:
3 Full speed USB ports (one in front, two in rear)
1 Gigabit ethernet port
Communication ProtocolsMODBUS, streaming
Depth (English)24 in.
Depth (Metric)609 mm
Description43iQ Sulfur Dioxide Analyzer
Detection Limit2 ppb (10 second averaging time)
1 ppb (60 second averaging time)
0.25 ppb (300 second averaging time)
Electrical Requirements100-240 VAC 50/60Hz, 275 Watts
Height (English)8.72 in.
Height (Metric)221.48 mm
Interferences(EPA Levels) Less than lower detectable limit except for the following:NO < 3 ppb, M-Xylene < 1ppb, H2O < 3% of reading
Measurement Range0-10 ppm, 0-25 mg/m^3; Extended: 0 to 100 ppm, 0 to 250 mg/m3
Outputs6 isolated analog voltages outputs, with 4 selectable ranges
6 isolated analog current outputs, with 2 selectable ranges; 8 solenoid driver outputs
10 digital reed relay contact outputs
Precision1% of reading or 1 ppb (whichever is greater)
Weight (English)37.1 lb.
Weight (Metric)16.8 kg
Width (English)16.75 in.
Width (Metric)424.45 mm
Zero Drift<0.5 ppb (24 hours)
Unit SizeEach