OCEANOGRAPHIC LOG SHEET D, PRNC-NHO-1191 

 (Rev. 6-53) 



CHLORINITY AND SALINITY DETERMINATION 



14-88 GENERAL REMARKS. The D- 



sheet is used for recording the chemical analyses 

 and calculations involved in the determination 

 of chlorinity and salinity of sea water samples 

 by the Knudsen method. Complete instruc- 

 tions for this method are given in chapter 13. 

 Study those instructions carefully before at- 

 tempting to use this log sheet. 



14-89 THE LOG SHEET.— A sample log 

 sheet is shown in figure 14-5. Print all entries 

 accurately and neatly. 



14-90 The Log Sheet Headings.— Fill in 

 the ship's name and number, cruise name and 

 number, and station number. The chemist's 

 name and the date of the analyses should be 

 entered in the proper spaces. The name, 

 or initials, of the oceanographer checking the 

 sheet will signify acceptance of the data as 

 to accuracy and correctness. 



14-91 the Log Sheet Columns.— The log 

 sheet columns are completed in accordance 

 with the instructions given below. 



14-92 Serial Number. — The serial number 

 is obtained from the serial number column 

 of the A-sheet for the station being analyzed. 



14-93 Sample Bottle Number. — ^The sample 

 bottle numbers are obtained from the A-sheet. 

 They are listed in the column headed CI 

 under Bottle Numbers. When copying these 

 numbers from the A-sheet be sure that they 

 agree with the serial numbers, line for line. 



14-94 First Burette Reading. — Record in this 

 column the reading of the Knudsen burette 

 for the first titration of each sea water sample. 

 These values are given on the burette in double 

 milliliters. They are recorded to two decimal 

 places. 



14-95 Second Burette Reading. — Record in 

 this column, the reading of the Knudsen burette 

 for the second titration of each sea water 

 sample. 



14-96 Third Burette Reading.— Record in 

 this column, the reading of the Knudsen 

 burette for the third titration of each sea 

 water sample. This titration is necessary only 

 when the first and second titrations differ 

 by more than 0.02. If the third titration 

 fails to agree within 0.02 of either of the first 

 two, continue running titrations until two 

 results are obtained that do agree within 0.02. 



Enter the value then obtained in the third 

 burette reading column. 



14-97 Average Burette Reading. — Average 

 the readings of the first and second and/or 

 third titrations, and record the average value 

 in this column. If more than 2 titrations are 

 made, average the 2 values that agree within 

 0.02. 



14-98 k — k is the correction needed to 

 convert the average burette reading to chlorin- 

 ity. k is given in the Hydrographical Tables 

 of 1901, by Martin Knudsen. These tables 

 are commonly referred to as Knudsen's Tables. 

 k is shown on the right-hand side of pages 23 

 through 34 of these tables. To obtain the 

 proper k enter the tables with the alpha value 

 (a), as determined by the standardization of 

 the silver nitrate solution. Select the column 

 having the proper alpha value, making sure 

 the correct sign (±) is used, and find the two 

 figures between which the average burette 

 reading of the water sample lies. Record k 

 with its proper sign on the D-sheet. If the 

 average burette reading is the same as the 

 one in the alpha column of the tables, then 

 select the nearest even k. 



14-99 Chlorinity °/oo' — Record in this col- 

 umn the chlorinity of each sea water sample 

 as expressed in parts per thousand (%o)- 

 This is the weight of chlorine, in grams, found 

 in 1,000 grams of sea water. This value is 

 obtained by adding algebraically the Average 

 Burette Reading and the k value for each 

 sample. 



14-100 Salinity °/ao- — Record in this column 

 the salinity of each sea water sample as ex- 

 pressed in parts per thousand and (°/oo)- 

 This is the total weight of salt, in grams, found 

 in 1,000 grams of sea water. This value can 

 be computed (S%o = 0.03+ 1.805XCl°/oo) but 

 may be obtained directly from table 16. 

 Enter the table with the chlorinity (Cl°/oo) 

 and read the salinity (S°/oo) directly from the 

 adjacent column to the right. These values 

 are then recorded on the E-sheet in the column 

 headed Salinity %o, under Observed Values. 

 Be sure values agree with the serial numbers 

 on the E-sheet, line for line. 



14-101 Time. — Record in this column the 

 time that the last titration of each sea water 

 sample was completed. 



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H. O. 607 



