
13
3. Dissolved Oxygen Mode
3.1 Selecting Dissolved Oxygen Mode
1. Select Mode (
→
→
F3:Mode
).
2. The Mode readout units selection screen is now displayed…
MODE
>F1:ppM F2:ppM (Sal)
F3:%Sat F4:%Gas
>F5:Cond. F6:TDS
The arrow indicates the current selection.
Press
to select Dissolved Oxygen readout in ppM units. This selection will not apply Salinity
correction to the displayed readings.
Press
to select Dissolved Oxygen readout in Salinity-corrected ppm units. This selection will
use the Conductivity or TDS reading for automatic Salinity correction.
Press
to select Dissolved Oxygen readout in % Saturation units.
Press
to select Dissolved Oxygen readout in % Gaseous units.
Press
to quit without changing the current setting.
3.2 Dissolved Oxygen Stirrer
The
smart
CHEM
-D
is equipped with a 4.5V DC output to power a stirrer for the Dissolved
Oxygen sensor. This power output is suitable for the YSI self-stirring BOD sensor (part number
123213), or the TPS submersible DO
2
stirrer (part number 123305).
The 4.5V output is available at the
Accessories
connector on the rear of the
smart
CHEM
-D
.
When using the YSI self-stirring BOD sensor (part number 123213), please use the optional adaptor
cable (part number 123311).
The Control output is capable of supplying 150 mA, which is ample for the two stirrers detailed
above.
3.2.1 Enabling and Disabling the Dissolved Oxygen Stirrer Output
1. Select the Ports menu (
→
→
F4:Setup
→
→
F4:Ports
).
2. Select
F3:Enable Stirrer
or
F3:Disable Stirrer
from the menu as required.
3.2.2 Starting and Stopping the Dissolved Oxygen Stirrer
1. Ensure that the Dissolved Oxygen stirrer output has been enabled, as per section 3.2.1.
2. Press
once in normal display mode to start the stirrer. The stirrer will stay on for 40 seconds
and then stop. A countdown is provided on the screen. The unit will beep every second for the
last five seconds.
3. Press
a second time any time during the 40 second period to set the Dissolved Oxygen stirrer
to operate continuously. The stirrer icon plus the word “
ON
” is shown on the display.
4. Press
a third time to stop the Dissolved Oxygen stirrer.
The operator has the choice whether or not to operate the Dissolved Oxygen stirrer during
automatic datalogging. See section 11.2.
Summary of Contents for smartCHEM-D
Page 60: ...60 ...