YSI Pro30 - Manual (Page 9)

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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.
sPecIfIc conductance temPerature
coeffIcIent (sPc %/°c)
SPC %/°C (Specific Conductance Temperature Coefficient) is the temperature
coefficient used to calculate Specific Conductance. The coefficient range is 0.00
to 4.00. The default value is 1.91% which is based on KCl standards.
To change the temperature coefficient, highlight SPC %/°C and press enter to
open the submenu. With the temperature coefficient 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 coefficient. Next, highlight the
ESC-Exit box and press enter to close the submenu.
tds constant
TDS Constant is a multiplier used to calculate an estimated TDS (Total Dissolved
Solids) value from conductivity. The multiplier is used to convert Specific
Conductance in mS/cm to TDS in g/L. The Pro30’s default value is 0.65. This
multiplier is highly dependent on the nature of the ionic species present in the
water sample. To be assured of moderate accuracy for the conversion, you must
determine a multiplier for the water at your sampling site. Use the following
procedure to determine the multiplier for a specific sample:
Determine the specific conductance of a water sample from the site; 1.
Filter a sample of water from the site; 2.
Completely evaporate the water from a carefully measured volume of 3.
the filtered sample to yield a dry solid;
Accurately weigh the remaining solid; 4.
Divide the weight of the solid (in grams) by the volume of water used 5.
(in liters) to yield the TDS value in g/L for this site;
Divide the TDS value in g/L by the specific conductance of the water in 6.
mS/cm to yield the conversion multiplier. Be certain to use the correct
units.
If the nature of the ionic species at the site changes between sampling studies, the
TDS values will be in error. TDS cannot be calculated accurately from specific
conductance unless the make-up of the chemical species in the water remains
constant.
To change the TDS Constant in the Pro30, highlight TDS Constant and press
enter to open the submenu. With the TDS Constant highlighted, press enter
to make the field adjustable. Next, use the up or down arrow key to increase or
decrease the value. The input range is 0.30 to 1.00. Press enter to save the new
TDS Constant. Next, highlight the ESC-Exit box and press enter to close the
submenu.
language
Highlight Language and press enter to open a submenu that allows you to
change the language. Highlight the desired language (English, Spanish, German,
or French) and press enter to enable. The enabled language will have an ‘X’ in the
box next to it. Highlight ESC-Exit box and press enter to save any changes and
to close the Language submenu.
The text in the boxes along the bottom of the Run screen will always be displayed
in English regardless of the language enabled in the System Setup menu.
auto shutoff
Auto Shutoff allows you to set the instrument to turn off automatically after a
period of time. Use the up or down arrow keys to highlight Auto Shutoff, then
press enter to open the submenu. Press enter while the minute field is highlighted
to make it adjustable. Next, use the up or down arrow keys to adjust the shut
off time from 0 to 60 minutes. Press enter to save the new shutoff time. Next,
highlight the ESC-Exit box and press enter to close the submenu.
To disable Auto Shutoff, set the Time in Minutes to 0 (zero).
cell constant
The Cell Constant displays the cell constant of the conductivity cell. The cell
constant is calculated and updated each time a conductivity calibration is
performed. The cell constant range is 4.0 to 6.0. Resetting the System Menu
resets the cell constant to 5.0.