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Ref. No. [UMCES] CBL 2016-012
ACT VS16-03
13
Table 1.
Dissolved oxygen temperature and salinity challenge trial conditions. For each trial pre and post
measurements of tank temperature (
o
C) and salinity (S) were made with an calibrated SBS26+4M CTD,
equilibrated in well mixed tank for 20 min until stable readings obtained.
Trial ID
Mean
Temperature
o
C
S.D.
Temperature
o
C
Mean
Salinity
PSU
S.D.
Salinity
PSU
Levels of
DO tested
mg/L
Figure
for
SBS
L_T15_S00
15.44
0.03
0.00
0.000
0, 2, 5,9,10,14
A
L_T15_S10
15.47
0.01
8.82
0.003
0, 2, 8, 9, 13
B
L_T15_S35
15.39
0.03
34.20
0.009
0,2,6,8,12
C
L_T04_S00
5.40
0.08
0.00
0.000
0,4, 12, 17
D
L_T04_S10
5.30
0.03
8.98
0.009
0, 5, 12, 16
E
L_T04_S35
5.23
0.07
34.77
0.073
0, 4, 10, 14
F
L_T30_S00
30.22
0.03
0.00
0.000
0, 3, 5, 9
G
L_T30_S10
30.51
0.12
9.28
0.036
0, 3, 7, 10
H
L_T30_S35
30.61
0.07
34.43
0.050
0, 2, 6, 9
I
The mean and standard deviation of the differences between the SBS HydroCAT and
reference measurements for each trial (n = 38 - 51) are presented in Table 2. Mean differences
among trials ranged from -0.012 to 0.132 mg/L over all nine trials. There was a noticeable
temperature effect in instrument response with offsets going from a mean of -0.082 to 0.103 across
the temperature trials of 4-15-30
o
C. There was no noticeable pattern to the magnitude or
direction of differences across the salinity trials of 0-10-35.
Table 2.
Summary of the mean and standard deviation of offsets between paired SBS DO sensor measures
and Winkler reference DO measures during laboratory trials.
Trial ID
Instrument – Winkler DO
mean
s.d.
Observed n Possible n
L_T15_S00
-0.012
0.031
51
51
L_T15_S10
-0.035
0.051
39
39
L_T15_S35
-0.034
0.068
38
38
L_T04_S00
-0.040
0.090
39
39
L_T04_S10
-0.099
0.181
36
36
L_T04_S35
-0.106
0.135
37
37
L_T30_S00
0.059
0.095
40
40
L_T30_S10
0.118
0.114
39
39
L_T30_S35
0.132
0.128
40
40
The precision of the SBS37 HydroCAT sensor was also characterized for each of the nine
temperatures and salinity trials (Table 3). Precision trials were conducted at the start of each new
tank test when conditions were most stable. Instruments were equilibrated in test tanks at indicated
temperature and salinities for 45 min then the subsequent 31 one-minute measurements were used
to estimate average tank DO (mg/L) and its variation over that interval. The absolute precision,