Dissolved oxygen
Multi 3320
46
ba77053e04
07/2018
Stability control
(AutoRead )
The stability control function (
AutoRead
) continually checks the stability of the
measurement signal. The stability has a considerable impact on the reproduc-
ibility of measured values (see section 10.2.3 A
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.
Freezes the mea-
sured value (HOLD
function)
With the HOLD function, you can freeze the current measured value. The dis-
played measured value stops changing until you switch the HOLD function off.
8.1.2
Measuring the temperature
For reproducible D.O. measurements, it is essential to measure the tempera-
ture of the test sample.
The temperature is automatically measured by the temperature sensor
(NTC30 or Pt1000) integrated in the sensor.
Measured parameter
Time interval
Stability in the time
interval
D.O. concentration
20 seconds
Δ
: better than 0.05 mg/l
D.O. saturation
20 seconds
Δ
: better than 0.6 %
D.O. partial pressure
20 seconds
Δ
: Better than 1.2 mbar
Temperature
15 seconds
Δ
: better than 0.5 °C
1.
Freeze the measured value with
<AR>
.
The [HOLD] status indicator is displayed.
2.
Release the frozen measured value again with
<AR>
.
The HOLD function is switched off.
The [HOLD] status display disappears.
