YSI 556 MPS - Manual (Page 48)

Section 6 Calibrate
YSI 556 MPS YSI Incorporated Page 42
NOTE: Make sure that the DO and temperature sensors are
not immersed in the water.
5. Engage only 1 or 2 threads of the transport/calibration cup to
ensure the DO sensor is vented to the atmosphere.
6. Use the keypad to enter the current local barometric pressure.
NOTE: If the unit has the optional barometer, no entry is
required.
NOTE: Barometer readings that appear in meteorological
reports are generally corrected to sea level and must be
uncorrected before use (refer to Section 10.10 Calibrate
Barometer, Step 2).
7. Press Enter. The DO% saturation calibration screen is
displayed.
Figure 6.9 DO Sat Calibration Screen
8. Allow approximately ten minutes for the air in the
transport/calibration cup to become water saturated and for
the temperature to equilibrate before proceeding.