YSI 6000UPG - Manual (Page 59)

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you will be able to follow the stabilization of the readings and confirm the calibration when the
readings are stable by pressing Enter as instructed on the screen.
Select this option to calibrate the oxygen probe in 100% water saturated air. Be certain that the
sensor has been thermally equilibrated in water-saturated air, and that the sensor shows stable
readings in Discrete Sample mode prior to beginning the calibration routine, particularly after a
membrane change. See section 3.2 for more details. Relieve pressure in the calibration cup, if
necessary. Remember that the 6000UPG transport cup is designed to be air tight and the vent
screw must be loosened if the vessel is used as a calibration chamber.
Then enter the local barometric pressure in mm Hg, press Enter, and the dissolved oxygen sensor
will calibrate. Approximately 1 minute is required for DO % calibration.
Select this option to calibrate the oxygen probe to a water sample which contains a known
concentration of dissolved oxygen. For this calibration procedure, the sensor should be immersed
in water containing a known concentration (mg/L) of dissolved oxygen, usually determined by
performing a Winkler titration. After thermal equilibration, enter this value, press Enter, and the 1
minute calibration procedure will begin.
Select this option to zero the depth sensor. The depth sensor is factory calibrated. It is, however,
necessary to zero the sensor with regard to the local barometric pressure. The zeroing procedure
should be carried out with the sonde suspended in air. Do not attempt to zero the depth probe when
the sonde is immersed. After the depth option is selected, enter 0.00 at the prompt, press Enter and
monitor the stabilization of the depth readings. After no changes occur for approximately 30
seconds, press Enter to confirm the calibration. As instructed, press any key to return to the
Calibrate menu.
Zeroing the depth sensor by the above protocol (entering 0.00 at the screen prompt) will result in a
measurement of the distance between the water surface and the bottom of the sonde bulkhead. This
bulkhead is approximately 0.46 ft above the bottom of the sonde guard. Thus, in order for the
observed depth to better reflect the distance between the water surface and the probe array, enter
0.46 at the screen prompt instead of 0.00.
Select this option to calibrate the ORP sensor. Immerse the ORP probe in a solution with a known
ORP value (we recommend Zobell solution) and press Enter. You will be prompted to enter the
ORP value of the solution as found on the bottle. Press Enter, and monitor the stabilization of the
2. DO %
3. DO mg/L
4. Depth
5. ORP