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Ref. No. [UMCES] CBL 2016-010
ACT VS16-01
42
RESULTS of MOORED FIELD TESTS
Moored field tests were conducted to examine the performance of the JFE AroW-USB to
consistently track natural changes in dissolved oxygen over extended deployment durations of 11-18
weeks. In addition, field tests examined the reliability of the instrument, i.e., the ability to maintain
integrity or stability of data collection over time. Reliability was determined by quantifying the
percent of expected data that was recovered and useable. The performance of the AroW-USB was
examined in three separate field deployment tests at various ACT Partner sites to include a range of
biogeochemical conditions. The range and mean for temperature and salinity for each test site is
presented in Table 7 The final reference temperature data was computed from the mean of two RBR
thermistors and a SeaBird SBE that were mounted at the same sampling depth as the test instrument.
Immediately before each deployment the JFE AroW-USB was exposed to a laboratory reference tank
for 3-4 measurements to confirm good working status and provide an initial offset against its latest
calibration (Table 8).
Table 7
. Range and average for temperature, and salinity at each of the test sites during the sensor field
deployments. Temperature and salinity were measured by at least 2 RBR temperature loggers and a SeaBird
SBE 26 (or SBE26plus) mounted on the instrument rack for the duration of the deployment.
SITE
(deployment period/duration)
Temperature
°
C )
Salinity
Keweenaw Waterway
Min.
0.04
0.0
9Jan – 22Apr
Max.
5.2
0.01
(n = 104 days)
Mean
0.7
0.01
Chesapeake Bay
Min.
19.3
4.7
20May – 5Aug
Max.
36.7
13.7
(n = 78 days)
Mean
25.6
10.9
Kaneohe Bay
Min.
23.1
27.3
24Sep – 21Jan
Max.
29.1
34.7
(n = 121 days)
Mean
25.8
33.4
Table 8.
Results of the pre-deployment check for the AroW-USB for each deployment site. The DO of the
reference solution is based on the mean of three Winkler titration analysis of the reference tank during the
exposure. Ambient water was used for the reference solution at each deployment site.
Deployment Site
Reference
Solution
Measurement
Temperature
Reference Solution
DO (mg/L)
Instrument
DO (mg/L)
MTU
Site Water
11.7
o
C
10.193
10.35
CBL
Site Water
21.6
o
C
7.983
7.88
HIMB
Site Water
26.6
o
C
6.547
6.49