A field intercomparison between a miniature CTD and the Neil Brown serial 1223 CTD- profiler

Abstract

During a survey in Lofoten in may 1989 a new miniature CTD which is being developed at the Inst. of Marine Research was mounted to the ship`s ordinary serial 1223 CTD- profiler on 10 different CTD- stations. Using the NB CTD as a reference and compensating for differences in sampling rate, the data presented from the two instruments when being in the same water volumes were compared. The experiments showed occational differences in the measurements of maximum 0.18 degr. C in temperature and 0.18 mmho/cm in conductivity. lf the miniature CTD is calibrated against the NB CTD and the water is homogenous, the differences in reading between the two instruments may be reduced to within +/- 0.02 degrees C and+/- 0.025 mmho/cm.