YSI 5200 - Manual (Page 62)

YSI Incorporated 60 5200 Recirculating System Monitor
Section 6. Calibration
All of the sensors, except temperature, require periodic calibration to assure high performance. You will
find specific calibration procedures for all sensors that require calibration in the following sections. If a
sensor listed is not installed in your probe module, skip that section and proceed to the next sensor until
the calibration is complete.
CAUTION: Reagents that are used to calibrate and check this instrument may be hazardous to your
health. Take a moment to review Section 18 Health and Safety. Some calibration standard solutions may
require special handling.
6.1 Getting Ready to Calibrate
6.1.1 Containers Needed to Calibrate the Probe Module
The calibration/storage cup that comes with the YSI 5562 Probe Module serves as a calibration chamber
for all calibrations and minimizes the volume of calibration reagents required.
Instead of the calibration/storage cup, you may use laboratory glassware to perform calibrations. If you do
not use the calibration/storage cup that is designed for the probe module, you are cautioned to do the
following:
Ö Perform all calibrations with the Probe Sensor Guard installed. This protects the sensors from
possible physical damage.
Ö Use a ring stand and clamp to secure the probe module body to prevent the module from falling
over. Most laboratory glassware has convex bottoms.
Ö Ensure that all sensors are immersed in calibration solutions. Many of the calibrations factor in
readings from other sensors (e.g., temperature sensor). The top vent hole of the conductivity
sensor must also be immersed during some calibrations.
6.1.2 Calibration Tips
Ö If you use the Calibration/Storage 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.
Ö The key to successful calibration is to ensure that the sensors (except DO) are completely
submersed when calibration values are entered. Use recommended volumes when performing
calibrations.
Ö 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.
Ö Fill a bucket with ambient temperature water to rinse the probe module between calibration
solutions.
Ö 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.