Starting at $4,256.00
  • Usually ships in 5-7 weeks



  • Measurement ranges
    0-10; 0-50; 0-100; 0-500; 0-1,000
    0-5,000; 0-10,000; or 0-20,000 ppm
  • ±1% of full scale accuracy
  • 90% of full scale in less than 10 seconds response time
  • 40 to 104°F (5 to 40°C) operating temperature range
  • Rechargeable NICAD batteries with universal AC charger
  • 1/4" stainless steel compression fittings
  • 2-year electronics and 1-year sensor warranty
  • 3-1/2 digit LCD
  • Polycarbonate-rated NEMA 1 enclosure


The AOI Series 3520 oxygen analyzer is portable, battery-operated, and designed for industrial and commercial applications where spot trace oxygen measurements are needed. The enclosure is made from durable polycarbonate, and is rated NEMA 1 for general purpose service.

The Series 3520 features an ambient-temperature electrochemical sensor. The enhanced mechanical design of the sensor ensures longer life, and virtually eliminates leakage of caustic electrolyte. The sealed sensor is not position-sensitive and does not require manual adjustment based on changes in the molecular weights of sample gases such as helium and hydrogen. The output from the sensor is both linear and temperature-compensated to provide optimum performance.

An optional CO2-tolerant trace oxygen sensor is capable of providing accurate oxygen readings in gases containing up to 100% CO2 without shortening the life of the sensor.