VWR MD 8000 L, Руководство по эксплуатации

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MD 8000 L Dissolved oxygen
ba77218e01 11/2018
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Criteria for a stable
measured value
The Stability control function checks whether the measured values are stable
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.
D.O. sensors measure the temperature with a temperature sensor integrated
in the sensor.
8.2 Calibration
8.2.1 Why calibrate?
D.O. sensors age. Aging changes the zero point 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
You can prematurely terminate the Stability control function manu-
ally with
<OK>
at any time. If the Stability control function is pre-
maturely terminated, the current measurement data are output to
the interface without the AutoRead info.
You can switch off the beep (see section 11.6 S
ENSOR
-
INDEPEN
-
DENT SETTINGS
, page 69).
3. Using
<OK>
, start a further measurement with stability control.
or
Release the frozen measured value again with
<HOLD>
or
<MODE>
.
The [AR] status display disappears. The display switches back to the
previous indication.
Measured parameter Time interval Stability in the time
interval
D.O. concentration 20 seconds
∆
: better than 0.03 mg/l
D.O. saturation 20 seconds ∆ : better than 0.4 %
Temperature 15 seconds
∆
: better than 0.5 °C