Understanding Oxygen & Nitrogen Analysis: Principle and Methods
Oxygen and nitrogen content affects the quality of steel, titanium, copper, ceramics and powder metals. Inert-gas fusion is the standard technique for measuring both elements in solid inorganic materials.
Principle
A pulse furnace heats a graphite crucible to 2000–3000 °C. Nitrogen in the sample is released as N₂, while oxygen reacts with the crucible carbon to form CO and CO₂. Oxygen is determined by infrared absorption of CO₂ (around 4.26 µm); nitrogen is determined by thermal conductivity.
Measurement range
Modern analyzers cover a wide range — from 0.00001% to 40% for both oxygen and nitrogen — and the range can be extended by changing the sample weight.
Common standards
- GB/T 11261, GB/T 20124, GB/T 14265
- ISO 10720, ISO 17053
- ASTM E1569, ASTM E1409, ASTM E1019
- JIS G1228, JIS G1201
Practical tips
- Prepare clean, dry samples and use the correct flux for your matrix.
- Run blanks and reference standards with each batch to monitor calibration.
- Use automatic leak check and gas-saving features to keep the gas path stable.
With the right method and standards, inert-gas fusion delivers fast, accurate oxygen and nitrogen results for everyday quality control.