Introduction to Nitric Oxide (NO)

Nitric Oxide (NO) is a colorless, non-flammable, poisonous, oxidizing gas with an irritating odor. Also known as Nitrogen Monoxide, it is an important intermediate in the chemical industry. It is a by-product of combustion of substances in air, as in vehicle engines and fossil fuel power plants. Nitric Oxide should not be confused with Nitrogen Dioxide (NO2), although it is rapidly oxidized in air to form Nitrogen Dioxide.

Nitric Oxide is extremely toxic when inhaled, and symptoms of over-exposure may not become apparent for up to 72 hours. Due to the gas being an oxidizer, it will support and enhance combustion. Personnel working with Nitric Oxide must proceed with extreme caution and have proper gas leak detection, especially in enclosed areas.

Health Hazards

When present in high concentrations through inhalation, Nitric Oxide may produce these symptoms:

  • Blurred vision
  • Confusion
  • Dizziness
  • Sweating
  • Muscle weakness
  • Unconsciousness
  • Oxygen deficiency

Exposure Limits

When researching NO gas detection solutions, facility managers should be aware of the following NO exposure limits:

Exposure Limits Agency
25 ppm TWA OSHA PEL (General Industry)
25 ppm TWA OSHA PEL (Construction Industry)
25 ppm TWA OSHA PEL (Maritime)
25 ppm TWA ACGIH TLV
25 ppm TWA NIOSH REL
100 ppm NIOSH IDLH

Products for NO Gas Detection

NO Gas Detectors

For further product information for detecting NO gas, contact your local Sierra Monitor sales representative.

Technology for NO Gas Detection

Electrochemical Sensors

Electrochemical sensors are fuel cell-like devices consisting of an anode, cathode, and electrolyte. The components of the cell are selected so that a subject gas, allowed to diffuse into the cell, will cause a chemical reaction and generate a current. The cells are diffusion-limited, meaning that the rate of the gas entering the cell is solely dependent on the gas concentration. The current generated is proportional to the rate of consumption of the subject gas in the cell.

Learn more about the advantages of using Sierra Monitor's electrochemical gas sensor modules »