Guildline Autosal 8400B - 6.3. CONVERTING INSTRUMENT READING TO SALINITY

Section 6
TM8400B-L-00
1 November 2004
6-5
6.3. CONVERTING INSTRUMENT READING TO SALINITY
The instrument reading is displayed in terms of
2  CONDUCTIVITIY RATIO OR 2R
t
of the sample to the sea-water standard. Convert the instrument reading to salinity value by using
one of the two following methods:
(1) Utilize the Unesco technical papers in marine science, No. 39 titled "International
oceanographic tables, Vol.3."
NOTE: Copies may be obtained from:
Division of Marine Sciences
Unesco
Place de Fontenoy
75700 Paris, France
or from most oceanographic libraries or institutes.
(2) Calculate salinity using the following equation:
SRaRaRaRaRaaPS US
ttttt

2
5
5
2
4
2
3
32
2
1
10
)(
 
 


2
5
5
2
4
2
3
32
2
1
10
151
15
ttttt
RbRbRbRbRbb
tk
t
S 



where:
a
0
= 0.0080 b
0
= 0.0005
a
1
= -0.1692 b
1
= -0.0056
a
2
= 25.3851 b
2
= -0.0066
a
3
= 14.0941 b
3
= -0.0375
a
4
= -7.0261 b
4
= 0.0636
a
5
= 2.7081 b
5
= -0.0144
a
i
= 35.0000 b
i
= 0.0000
t = the bath temperature in °C
k = 0.0162
This calculation is valid over the salinity range from 2 PSU to 42 PSU.
These tables and the equation are based on the definition and the algorithm of practical
salinity formulated and adopted by the Unesco/ICES/SCOR/IAPSO Joint Panel on
Oceanographic Tables and Standards, Sidney, B.C., Canada, 1980.