YSI Pro30 - Manual (Page 8)

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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 four 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 Pro30 can display non-temperature compensated conductivity as well as
temperature compensated Specific Conductance. If Specific Conductance is
selected, the Pro30 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 Pro30’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
conductIvIty auto staBle (cond. auto staBle)
Auto Stable utilizes preset values to indicate when a reading is stable. The preset
values are adjustable in the System Setup menu. The user can input a % change
in readings (0.0 to 1.9) over ‘x’ amount of time in seconds (3-19).
Highlight Cond. Auto Stable, then press enter to open the submenu.
Use the up or down arrow keys to highlight the % change or seconds (secs) input
field, then press enter to make the highlighted field adjustable. Use the up or
down arrow keys to adjust the selected value, then press enter to confirm changes.
once you have confirmed any changes, highlight the ESC-Exit box along the
bottom of the display and press enter to close the Auto Stable submenu.
To disable Auto Stable, set the % Change input to 0.0.
When Auto Stable is enabled, an AS symbol will display next to the reading
on the Run screen and blink during stabilization. When the dissolved oxygen
and/or conductivity reading stabilizes based on the Auto Stable settings, the
AS symbol will display steadily and the instrument will beep twice if Audio
is turned on.
temPerature unIts
Highlight Temperature Units and press enter to open a submenu that allows
you to change the temperature units displayed on the Run screen. Highlight
the desired unit (Celsius or Fahrenheit) and press enter to enable. The enabled
temperature unit will have an ‘X’ in the box next to it. only one unit may be
enabled at a time. Highlight the ESC-Exit box and press enter to save any changes
and to close the Temperature Units submenu.