YSI 556 MPS - Manual (Page 39)

Calibrate Section 6
YSI Incorporated YSI 556 MPS Page 33
6.1.2 Calibration Tips
1. If you use the Transport/Calibration Cup for dissolved oxygen
(DO) calibration, make certain to loosen the seal to allow
pressure equilibration before calibration. The DO calibration
is a water-saturated air calibration.
2. When calibrating pH, always calibrate with buffer 7 first,
regardless if performing a 1, 2, or 3 point calibration
3. The key to successful calibration is to ensure that the sensors
are completely submersed when calibration values are
entered. Use recommended volumes when performing
calibrations.
4. For maximum accuracy, use a small amount of previously
used calibration solution to pre-rinse the probe module. You
may wish to save old calibration standards for this purpose.
5. Fill a bucket with ambient temperature water to rinse the
probe module between calibration solutions.
6. Have several clean, absorbent paper towels or cotton cloths
available to dry the probe module between rinses and
calibration solutions. Shake the excess rinse water off of the
probe module, especially when the probe sensor guard is
installed. Dry off the outside of the probe module and probe
sensor guard. Making sure that the probe module is dry
reduces carry-over contamination of calibrator solutions and
increases the accuracy of the calibration.
7. If you are using laboratory glassware for calibration, you do
not need to remove the probe sensor guard to rinse and dry the
sensors between calibration solutions. The inaccuracy
resulting from simply rinsing the sensor compartment and
drying the outside of the guard is minimal.
8. If you are using laboratory glassware, remove the stainless
steel weight from the bottom of the probe sensor guard by
turning the weight counterclockwise. When the weight is
removed, the calibration solutions have access to the sensors