2 limits t, Limits t – Metrohm 781 pH/Ion Meter User Manual
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6.3 Temperature measurement (T mode)
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This reference value is subtracted from the measured value itself. The
modified measured value is shown together with this value and is taken
into consideration, for example, in checking the limit values (see
PA-
RAMETER T/limits T
). The reference value is not included in the re-
port. However, should you still want to document it then you should al-
so produce a parameter report (see Section 7.2.7).
stirrer:
ON, OFF, control
You can choose whether the pH measurement is to be made while stir-
ring is being carried out or not. A requirement is that a Metrohm stirrer
is connected with a suitable cable (see Section 2.3). If an 8xx series stir-
rer has been connected and the settings made under
CON-
FIG/peripheral units
then the stirring rate can also be selected:
stirring rate
1...5...15
If you want your measurement to be made without stirring but still want
to stir the solution before the measurement then you should select the
control
setting. In this way you can trigger a stirring sequence before
the start of each measurement with <MEAS/PRINT>:
prestir pause
0...99999 s
stir time
0...99999 s
poststir pause
0...99999 s
The prestir and poststir pauses represent waiting periods in which stir-
ring does not take place. The measurement itself only starts when the
complete stirring sequence has ended. Please note that this parameter
is binding for the report output and for storing a measured value. There-
fore when you start a measurement with <MEAS/PRINT> the stirrer will
be switched on and off accordingly. This is why you should preferably
carry out drift-controlled measurements (see Section 5.2 and Sec-
6.3.2
Limits T
PARAMETER T
:
├
limits T
: └
state
In the direct measuring modes the pH/Ion Meter has a limits function
which allows the control of the parameter to be monitored. The control
signals are transmitted via the MSB connection to the optional remote
interface (6.2148.010) (see Section 9.5). Out of limits conditions are al-
so shown on the display and documented in the report.
state:
ON, OFF
u.limit
-999.9...100.0...999.9 °C
u.hyst.
-999.9...0.2...999.9 °C
l.limit
-999.9...0.0...999.9 °C
l.hyst.
-999.9...0.2...999.9 °C