Manual Aqua M300D
page 23
The digit display now shows two values: the relative measured value (relative to the defined reference value, 000
display at the point of zero calibration) as large digits in the middle of the digit display and the measured absolute
measurement value beneath as reference value when zero calibration was carried.
The displayed values change as follows when the hydrogen concentration increases:
the relative measured value shows the increasing values in relation to the defined reference value. The absolute
measured value shows the actual existing hydrogen concentration. The relative measured value is not only
displayed on the digital display but also on the red bar display as well as on the numerical display below.
If the hydrogen concentration values decrease below the defined reference value, the displayed relative
measured value no longer changes (000), but the absolute measured value still displays the existing hydrogen
concentration.
Here an example to explain how this works:
There are three different hydrogen concentrations in three fictive adjoining zones. The concentration in Zone 1 is
250 digits, the concentration in Zone 2 is 300 digits, and the concentration in Zone 3 is 100 digits.
1.
2. 3. 4.
1 First measuring is carried out in Zone 1; the measured value on the display is 200 digits
2 Now a zero calibration is carried out in zone 1 and the existing hydrogen concentration (250 digits) is defined
as the reference value. When a second measurement is carried out in Zone 1, the digital display now shows a
relative measured value of 000 and an absolute measured value of 200.
3 A new measurement is carried out in Zone 2. The digital display now shows a relative measured value of 50
and an absolute measured value of 300.
4 Then measuring is carried out in Zone 3. After the measurement has been carried out, the digital display only
shows the absolute measured value of 100 and no measuring value (000).
NOTE: The defined alarm thresholds are always set with regard to the relative measured value!
An alarm
threshold of 150 digits, as shown in the example above, would only trigger a signal after the first measurement in
zone 1 before zero calibration although the absolute measured value that was measured in Zone 1 (after zero
calibration)
and
in Zone 2 was above the alarm threshold
9.6 Clearing the Measurement Series
The current measurement series is cleared by keeping the right-hand key for a while.