YSI MultiLab 4010-3 - Manual (Page 71)

MultiLab 4010-3 Dissolved oxygen (D.O.)
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within the monitored time interval.
The minimum duration until a measured value is assessed as stable is the mon-
itored time interval. The actual duration is mostly longer.
8.1.2 Measuring the temperature
For reproducible D.O. measurements, it is essential to measure the tempera-
ture of the test sample.
IDS D.O. sensors measure the temperature with a temperature sensor inte-
grated in the IDS sensor.
8.2 Calibration
8.2.1 Why calibrate?
D.O. sensors age. This changes the zero point (asymmetry) and slope of the
D.O. sensor. As a result, an inexact measured value is displayed. Calibration
determines and stores the current values of the zero point and slope.
8.2.2 When to calibrate?
 When the calibration interval has expired
 When your accuracy requirements are especially high
 Routinely within the framework of the company quality assurance
8.2.3 Calibration procedures
The MultiLab 4010-3 provides 2 calibration procedures:

Calibration in water vapor-saturated air.
 Calibration via a comparison measurement (e.g. Winkler titration according
to DIN EN 25813 or ISO 5813). At the same time, the relative slope is
adapted to the comparison measurement by a correction factor. When the
correction factor is active, the [Factor] indicator appears in the measuring
window.
Calibration can be carried out either as a 1-point calibration or 2-point calibra-
tion procedure.
Measured parameter Time interval Stability in the time
interval
D.O. concentration 20 seconds Δ : better than 0.03 mg/l
D.O. saturation 20 seconds Δ : better than 0.4 %
Temperature 15 seconds Δ : Better than 0.5 °C