YSI Pro2030 - Manual (Page 11)

14 15
do unIts
Highlight Do Units and press enter to open a submenu that allows you to select
the dissolved oxygen units to be displayed on the Run screen. Highlight a unit
and press enter to enable or disable it. An enabled dissolved oxygen unit will
have an ‘X’ in the box next to it. Highlight the ESC-Exit box along the bottom
of the display and press enter to save any changes and to close the Do units
submenu.
There are three options for displaying dissolved oxygen:
mg/L will show Do readings in milligrams per liter on a scale from 0 •
to 50 mg/L.
ppm (parts per million) is equivalent to mg/L and will show the Do •
reading on a scale from 0 to 50 ppm.
% will show Do readings in a % saturation from 0 to 500%. This value •
will be expressed as %L when Do Local% is enabled.
mg/L and ppm cannot be enabled and therefore displayed at the same time.
Do% and mg/L or ppm can be enabled and displayed simultaneously.
conductIvIty unIts (cond. unIts)
Highlight Cond. Units (Conductivity Units) and press enter to open a submenu
that allows you to select the conductivity units to be displayed on the Run screen.
Highlight a unit and press enter to enable or disable it. An enabled conductivity
unit will have an ‘X’ in the box next to it. Highlight the ESC-Exit box along
the bottom of the display and press enter to save any changes and to close the
conductivity units submenu.
There are seven options for displaying conductivity. only two units can be
enabled at the same time:
CoND-mS/cm displays conductivity in milliSiemens per centimeter. •
CoND-uS/cm displays conductivity in microSiemens per centimeter. •
SPC-mS/cm displays Specific Conductance in milliSiemens per •
centimeter. Specific Conductance is temperature compensated
conductivity.
SPC-uS/cm displays Specific Conductance in microSiemens per •
centimeter. Specific Conductance is temperature compensated
conductivity.
Sal ppt displays salinity in parts per thousand. The salinity reading is •
calculated from the instrument’s conductivity and temperature values
using algorithms found in Standard Methods for the Examination of
Water and Wastewater.
TDS g/L displays • Total Dissolved Solids in grams per liter. TDS is
calculated from conductivity and temperature using a user-selectable
TDS constant.
TDS mg/L displays • Total Dissolved Solids in milligrams per liter. TDS
is calculated from conductivity and temperature using a user-selectable
TDS constant.
Note: 1 milliSiemen = 1,000 microSiemens.
SPECIFIC CoNDUCTANCE
The conductivity of a sample is highly dependent on temperature, varying as
much as 3% for each change of one degree Celsius (temperature coefficient =
3%/°C). In addition, the temperature coefficient itself varies with the nature of
the ionic species present in the sample. Therefore, it is useful to compensate for
this temperature dependence in order to quickly compare conductivity readings
taken at different temperatures.
The Pro2030 can display non-temperature compensated conductivity as well
as temperature compensated Specific Conductance. If Specific Conductance is
selected, the Pro2030 uses the temperature and conductivity values associated
with each measurement to calculate a specific conductance value compensated
to a user selected reference temperature, see below. Additionally, the user can
select the temperature coefficient from 0% to 4%.
Using the Pro2030’s default reference temperature and temperature coefficient
(25 °C and 1.91%), the calculation is carried out as follows:
Specific Conductance (25°C) = Conductivity of sample
1 + 0.0191 * (T - 25)
T = Temperature of the sample in °C
sPecIfIc conductance reference
teMPerature (sPc ref. teMP.)
SPC Ref. Temp. (Specific Conductance Reference Temperature) is the reference
temperature used to calculate Specific Conductance. The reference temperature
range is 15 and 25 °C. The default value is 25 °C.
To change the reference temperature, highlight SPC Ref. Temp. and press enter
to open the submenu. With the reference temperature highlighted, press enter
to make the field adjustable. Next, use the up or down arrow key to increase
or decrease the value. Press enter to save the new reference temperature. Next,
highlight the ESC-Exit box and press enter to close the submenu.