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Ref. No. [UMCES] CBL 2015-012
ACT VS15-05
Once a week multiple reference samples were collected from the test tank in a burst, i.e.
sampled as rapidly as possible (including analysis time) to examine heterogeneity within the test
tank and repeatability of the reference pH results. The average standard deviation of the
reference pH value for ten burst sampling events was 0.0025 with a range of 0.0055 to 0.0005
(Table 1).
Table 1.
Results of burst sample analysis for the Lab Test to demonstrate consistency of test tank
conditions and repeatability of dye pH measurements.
Date
Measurement
Temperature
(
o
C)
Salinity
Time Interval
(min)
(# Obs)
Mean
Std Dev
CV
12/11/12
20.4
35
24 (n=5)
7.783
0.0021
0.026
12/15/12
20.7
35
10 (n=3)
7.762
0.0035
0.045
12/18/12
11.0
35
16 (n=4)
7.867
0.0017
0.022
1/4/13
29.8
22
8 (n=2)
7.973
0.0018
0.023
1/8/13
12.0
22
30 (n=5)
8.141
0.0055
0.068
1/15/13
20.5
22
29 (n=5)
7.860
0.0005
0.001
1/31/13
12.5
0.3
35 (n=5)
8.277
0.0054
0.065
2/6/13
20.4
0.3
65 (n=5)
7.881
0.0024
0.030
2/8/13
30.4
0.3
60 (n=5)
7.644
0.0013
0.018
2/12/13
25.5
34
39 (n=5)
7.934
0.0010
0.013
Overall Average
0.0025
0.032
Due to an electronics problem with one of the circuit boards there was no reportable data
for the SeaFET. The instrument was confirmed to be operating over a three day period prior to
deployment within the test tank but then failed immediately upon the start of the test. No
handling problems or accidents were noted by the ACT staff or Chief Scientist during the
deployment. The failure was discovered only upon final retrieval so unfortunately no
replacement was attempted.