The analytical systems being automated or partially automated and 

 interfaced with the computer are the salinometer; alkalinity-total CO2 

 titration; gas chromatograph (total CO^, N„ A); autoanalyzer (NO3, 

 NO,, P0„ SiOs) ; Rn222. 



Data from the thermosalinagraph, atmospheric sensors, ship speed 

 and heading, satellite navigation, etc., will automatically and constantly 

 be added to the computer data bank, available for instant recall. 



a) Salinometry 



In order to reduce this task to a manageable time span, a new 

 temperature and salinity probe developed at the Woods Hole Oceano- 

 graphic Institution has been interfaced with a computer to provide nearly 

 instantaneous salinity measurements to a resolution of ± 0.002 parts 

 per mille. 



b) Alkalinity — Total CO2 



Analysis of Alkalinity-Total CO, is by one of three methods. Per- 

 formance of each method is being studied to determine which gives the 

 most precision and the most information. The three methods are: 1) the 

 Gran plot method described by Edmond; 2) determination of end point 

 by searching for the infection points on the titration curve; and 3) fit- 

 ting the observed data to the best available titration curve by means of 

 a non-linear least squares computer procedure. 



c) Argon and Nitrogen 



Two chromatographs will be used aboard ship, one for the analysis 

 of total CO2 and another for the analysis of dissolved argon and nitrogen. 

 The two chromatographs operate concurrently and are contained in the 

 same enclosure. The total CO2 gas chromatograph uses a thermal detector ; 

 the argon-nitrogen an ultrasonic detector. 



d) Nutrients 



The nutrients phosphate, silicate, nitrate, and nitrite are measured 

 using a Technicon Auto Analyzer system. However, manual spectro- 

 photometry is used frequently to check the calibrations of the auto ana- 

 lyzer. Data from a four-channel auto analyzer are converted to digital 

 form by panel meters and transmitted to the shipboard computer through 

 a data multiplexer. The manual spectrophotometer has its own digital 

 output and this transmits via the multiplexer to the computer. Sampling 

 sequences are transmitted by typewriter. 



e) Radon 



Excess radon gas will be measured in both surface and near-bottom 

 profiles at each station. The radon will be extracted from samples by 

 flushing with helium and freezing at liquid nitrogen temperatures. Four 

 extraction systems will be in use at all times. The extraction time is 

 approximately 2 hours. Following purification to remove water and carbon 

 dioxide the radon gas is transferred to a counting system consisting of 

 eight scintillation tubes. 



All of the automated systems described in the previous paragraphs 

 will be provided with backup manual methods. A Washington bridge 

 salinometer will be carried aboard ship, and manual alkalinity determina- 

 tions could be performed using a pH meter. Both the gas chromatographs 



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