The measurements of total carbon dioxide in dilute tropical waters

Abstract

A shipboard conductivity technique to measure the total carbon dioxide in dilute tropical water is described. The standard error of a single determination in the range 40-100 mg CO₂/I is 6.0 mg/l. There were 41-102 mg CO₂/l in waters of the Gulf of Thailand. In these waters, primary production determined with the usually assumed value of 90 mg CO₂ gave errors ranging from 11 to 120% for the individual depth samples and from 6 to 92 % for column values as compared to the values obtained using the measured CO₂ concentration.