720 °C catalytic thermal decomposition/chemiluminescence methods are adopted for TN measurement. There is no interference from metallic ions or bromine in sea water.

Measurements over a wide range with a detection limit of 5 μg/L for TOC-LC*H to an upper limit of 10,000 mg/L.

(In the case of simultaneous TOC/TN measurement, TOC analysis using high-sensitivity catalysts is impossible. TN measurement is not possible in combination with the SSM-5000A.)