Apollo SciTech’s AS-spec-pH1 Analyzer has been developed for high precision and accuracy, automated and fast determination of seawater pH. It is based on the principle of colorimetric determination of the relative color intensity using a pH indicator (m-cresol purple) at three wavelengths (434nm, 578nm, 730nm) with the first two absorptions as a known function of pH, and the third one serves as a baseline correction (Clayton and Byrne 1993; Liu et al. 2011). The automated analyzer is designed according to that of Carter et al. (2013) with improvements. A high quality Agilent spectrophotometer (model 8453) is used for the colorimetric determination and a high precision Kloehn digital pump is used for the delivery of pH indicator and the sample.