YSI 600LS - User Manual - Manual (Page 47)

Sondes Section 2
YSI Incorporated Environmental Monitoring Systems Operations Manual 2-41
NOTE: The YSI conductivity system is very linear over its entire 0-100 mS/cm range. Therefore, it is
usually not necessary to use calibration solutions other than the 10 mS/cm reagent recommended above for
all environmental applications from low conductivity freshwater to seawater. YSI does offer the 3161
(1 mS/cm) and 3165 (100 mS/cm) conductivity standards for users who want to assure maximum accuracy
at the high and low ends of the sensor range. Users of the 1 mS/cm standard should be particularly careful
to avoid contamination of the reagent. In fact, because of contamination issues, YSI does not recommend
using standards less than 1 mS/cm.
NOTE: For calibration of the 600 OMS V2-1conductivity sensor, the optical probe must be removed and
the port plugged. See specific instructions in the application note supplied with the 600 OMS V2-1.
RAPID PULSE POLAROGRAPHIC DISSOLVED OXYGEN
Place approximately 3 mm (1/8 inch) of water in the bottom of the calibration cup. Place the probe end of
the sonde into the cup. Make certain that the DO and temperature probes are not immersed in the water.
Engage only 1 or 2 threads of the calibration cup to insure the DO probe is vented to the atmosphere. Wait
approximately 10 minutes for the air in the calibration cup to become water saturated and for the
temperature to equilibrate.
Two calibration protocols are provided below for Rapid Pulse dissolved oxygen, one for sampling
applications and one for long-term monitoring applications.
Sampling Applications
If your instrument will be used in sampling applications where the dissolved oxygen is “on” continuously
during the study, deactivate “Autosleep RS232” as described in Section 2.5, Sonde Software Setup.
From the Calibrate menu, select Dissolved Oxy, then 1-DO % to access the DO percent calibration
procedure. Calibration of dissolved oxygen in the DO % procedure also results in calibration of the DO
mg/L mode and vice versa.
Enter the current barometric pressure in mm of Hg. (Inches of Hg x 25.4 = mm Hg).
Note: Laboratory barometer readings are usually “true” (uncorrected) values of air pressure and can be used
“as is” for oxygen calibration. Weather service readings are usually not “true”, i.e., they are corrected to sea
level, and therefore cannot be used until they are “uncorrected”. An approximate formula for this
“uncorrection” (where the BP readings MUST be in mm Hg) is:
True BP = [Corrected BP] – [ 2.5 * (Local Altitude in feet above sea level/100)]
Press Enter and the current values of all enabled sensors will appear on the screen and change with time as
they stabilize. Observe the readings under DO%. When they show no significant change for approximately
30 seconds, press Enter. The screen will indicate that the calibration has been accepted and prompt you to
press Enter again to return to the Calibrate menu.
Rinse the sonde in water and dry the sonde.