Sensor Specification; Optional Sensor Specifications; The Sensors; The Pressure Sensor - idronaut Ocean Seven 304Plus Operator's Manual

SECTION ONE – SYSTEM DESCRIPTION

1.12. SENSOR SPECIFICATION

The OS304Plus CTD can be equipped with the following sensors to measure:
Parameter
Pressure
Temperature
Conductivity
Analogue
(1) Other standard pressure transducers available have : 10, 40, 100, 200, 500, 2000, 4000, 7000 dbar ranges.
(2)At 1 m/second flow rate.
(3) Six analogue inputs available for future expansion.
(4) OS304Plus – MI version, special extended measurement range.
(*) By reducing the range to 0..70 mS/cm, the resolution becomes 0.0002 mS/cm.

1.13. OPTIONAL SENSOR SPECIFICATIONS

The OCEAN SEVEN 304Plus CTD can be optionally equipped with the IDRONAUT Highly Accurate
Precise (0.01%) pressure transducer, the IDRONAUT OEM Turbidity Meter and the IDRONAUT
dissolved oxygen sensor.
Parameter
Pressure
Oxygen
Turbidity Meter
(*) from nitrogen to air.
A detailed description of the optional sensors can be found in the dedicated appendices.

1.14. THE SENSORS

A short presentation of the standard IDRONAUT OCEAN SEVEN 304Plus sensors follows.

1.14.1. The pressure sensor

The pressure sensor is a high quality strain gauge, centrally mounted on the CTD base, capable of
generating a linear signal output thus giving a resolution of 0.03% over the whole measuring range of
0 - 700 bar.
Type:
Measurement range:
Accuracy:
Resolution
Response time:
Measurement bridge resistance:
Excitation current:
Insulation:
Operating temperature:
Sensor body:
Compensation:
Life:
Calibration:
IDRONAUT – Brugherio (MB)
Range
0..1000 dbar (1)
-5.. +35 °C
+35.. +45 °C
0.. 90 mS/cm(*)
0..5000 mV
Range
0..7000 dbar
0.. 50 pm
0.. 500 % sat.
0.03..750 FTU/NTU
0.03..500 FTU/NTU
0.03..125 FTU/NTU
0.03.. 25 FTU/NTU
strain gauge.
0..700 bar.
0.05%FS.
0.0015%FS.
50 ms @1 m/s.
@ 25°C 3500 Ω ± 20%.
0.6 mA.
@ 50 VCC 100 MΩ
-30..100 °C
AISI 316 L.
Automatic
compensated for the barometric pressure variations.
unlimited.
offset calibration in air.
OCEAN SEVEN 304Plus CTD
Accuracy Resolution
0.05 %F.S. 0.0015 % F.S.
0.002 °C 0.0001 °C
0.01 °C 0.0001 °C
0.003 mS/cm 0.0003 mS/cm
1 mV 0.1
Accuracy Resolution
0.01% F.S. 0.002 % F.S.
0.1 ppm 0.01 ppm
1 % sat. 0.1 %sat.
5 FTU/NTU 0.5 FTU/NTU
1 FTU/NTU 0.1 FTU/NTU
0.25 FTU/NTU 0.025 FTU/NTU
0.05 FTU/NTU 0.005 FTU/NTU
compensation
Time Constant
50 ms
50 ms
50 ms
50 ms
mV 50 ms
Time Constant
50 ms
3s (*)
3s (*)
0.1 s
0.1 s
0.1 s
0.1 s
for temperature variations.
9
(4)
(2)
(3)
Not
12-2015