Model 42i-HL High Level NO-NO2-NOx Analyzer

Measure high levels of nitrogen oxides in the air using chemiluminescence with the Thermo Scientific™ Model 42i-HL NO-NO2NOx Analyzer. The Model 42i-HL is a single chamber, single photomultiplier tube design that cycles between NO and NOx modes and can be operated continuously in either NO or NO x modes allowing for a response time of fewer than 5 seconds.

Discover the iQ to work smarter with our next-generation 42iQ High-Level NO-NO2-NOx Analyzer.

Key Features:

  • Standard single, dual, and auto ranges
  • Linearity through all ranges
  • Independent NO-NO2-NOx ranges
  • Replaceable NO2 converter cartridge

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 AnalytesNO, NO2, NOX
Flow Rate25 mL/min.
Inputs16 Digital Inputs (Standard), 8 0 to 10 VDC Analog Inputs (Optional)
Linearity±1% full scale
Response Time2.5 sec. NO Mode; 5.0 (Rise Fall Times 0-90%)
Span Drift±1% full scale
Zero Noise25 ppb
Certifications/ComplianceETL, CSA, UL, CE, UKCA
Depth (English)23 in.
Depth (Metric)584 mm
DescriptionHigh Level Nitrogen Oxide Monitor
Height (English)8.62 in.
Height (Metric)21.9 cm
Measurement Range0-10, 20, 50, 100, 200, 500, 1000, 2000, 5000ppm
OutputsSelectable voltage, RS232/RS485, TCP/IP, 10 status relays, and power fail indication (standard); 0-20 or 4-20mA isolated current output (optional)
Voltage100/115/220/240 V
Weight (English)70 lb.
Weight (Metric)31.75 kg
Width (English)16.75 in.
Width (Metric)425.45 mm
Zero Drift50ppb
Unit SizeEach