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The Nova 321 Portable Process Oxygen Analyzer utilizes a reliable, stable oxygen sensor which responds quickly to the oxygen present in a gas sample.  Its life expectancy is between 3 and 4 years.  The sensor is not affected by acidic gases such as carbon dioxide or sulfur dioxide and can operate in a background of hydrogen and many other gases.  It is very easy for the customer to replace and at a resonable price.

A rechargeable 'gel cell' battery provides enough power for the pump and electronics for about 20 hours of continuous operation. The analyzer may still be operated while it is being charged.  A red LED indicates when to recharge the analyzer and a green LED indicates that it is receiving recharging power.  The batter recharger is included with the analyzer.

The detected O2 is displayed on an LCD digital meter that has a switchable backlight for use in dark areas.  The analyzer is supplied with a 12ft. sample hose and either a sample pump or pressure regulator.

Unit of Measure


Method of Detection

N/A Long life electrochemical sensor

Ranges Available

N/A 0-5.0%, 0-10.0%, 0-25.0% and 0-50.0%


N/A 0.1% O2

Accuracy & Repeatability

N/A ±1% of full scale (±2% over 30% O2)


N/A <2% full scale for 8 hours of operation

Response Time (T-90)

N/A 8-10 seconds for 90% of step change

Ambient Temperature Range

N/A 0-40 ºC32-105 ºF


N/A ±1.0% of full scale

Size & Weight

N/A 10" L x 7 1/2" H x 6 1/2" D @ 8 lbs (25.5 x 19 x 16.5 cm @ 3.6kg)


N/A AC/DC operation. 115 VAC 60 Hz for recharging (Other voltages available)

Output Options

N/A 0-1V or 4-20mA (optional)

Hazardous Area Rating Options

N/A General Purpose, Non-Hazardous


N/A Analysis of oxygen (O2) concentration in industrial process gas or purging and blanketing gases



  • Rugged design that is easy to operate and maintain
  • Fast warm-up and response
  • Long life 'fuel cell' oxygen sensor (3-4 year life)
  • Digital readout meter with backlight
  • Rechargeable battery operation
  • Built-in sample pump or pressure regulator, filter and flow meter
  • Weatherproof (WP) cabinet with clear Lexan cover
  • Stainless steel probe with sample hose



  • Outputs of 0-1V or 4-20mA
  • Sample pre-cooler for hot or wet sample gases
  • Suitcase (K) style cabinet available
  • AC only power operation
  • Detachable/portable data logger



  • On air for span
  • On nitrogen for zero

Unique Applications

N/A All Nova analyzers are built using proven technologies and techniques. If this product does not suit your application, please contact Nova. In many cases, we are able to build an analyzer specific to your needs.

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