Download Appendix A - Horry County Stormwater

Environmental Quality Lab
Chemistry Procedures
SOP No.: 420
Page 8 of 15
Rev. 2
10-15-09
make sure the probe is set to read salinity (the main menu will show ‰ as the unit). If
needed, follow section 5.5.1 to change the parameter to salinity.
x
Clean the conductivity probe with deionized water and a brush if necessary. Dry the
probe with a soft cloth or paper towel.
x
Perform a reading in air by pressing the green “Read” button and waiting for the
reading to stabilize. If the reading is ” 0.01 µS/cm the probe is clean and ready to
calibrate.
x
Note: All conductivity probe calibrations are performed using conductivity units µS/cm
or mS/cm regardless of whether conductivity, resistivity, salinity, or total dissolved
solids (TDS) is measured.
x
If necessary, remove the plastic protective bell from the Conductivity probe by
loosening the fitting ring and sliding the bell off. If the bell will remain on the probe
make sure that the holes in the bell line up so that you can see through the bell and
through the conductivity chamber. This is to make sure there is free flow through the
chamber.
x
Place probe in the conductivity calibration standard, tilt and jiggle the probe to remove
air bubbles which will prevent an accurate result.
x
With the meter powered on and the conductivity probe connected:
o If the calibration screen is displayed, press cancel so you can perform a
precalibration measurement.
o Push the green button to ‘Read’ and once the reading is displayed fill in the
pre-calibration row in the conductivity probe calibration section on the “HACH
Ruggedized Field Probe CALIBRATION SHEET”
o Press the blue button to ‘Calibrate’, and then the green button to ‘Read’. Once
the calibration reading stabilizes record the calibration information on the
calibration sheet, push ‘Done’ and record that information on the calibration
sheet, and finally press ‘Store’ to save the calibration
o If the calibration was successful, the display screen will show OK in the top
left corner of the main menu. If it was not successful, repeat the calibration.
o Before removing the probe from the conductivity calibration standard, push
‘Read’ to perform a post-calibration reading. Record this reading on the
calibration sheet as well.
x
Rinse the conductivity probe and dry it. Perform a post calibration salinity control
sample reading and fill in that section on the calibration sheet.
x
Conductivity probe saves its calibration within itself (intelliCAL), so it can be
disconnected and reconnected to the same or another multi-meter and not need
recalibration.
x
Proceed with sample analyses or turn power off.
5.5.3
Sample Measurement for Salinity