Metrohm 781 pH/Ion Meter - Manual (Page 83)

6 Methods / Parameters
780/781 pH/Ion Meter, Manual
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measured value is to be stored or documented by printing a report (see
print criterion and storage criterion in Section 5.2 and Section 5.3).
Please note that for a drift-controlled measured value recording this drift
parameter must not be set to ' OFF ', as otherwise no result will be ex-
ported.
If this drift condition is not fulfilled then this is indicated by two constant-
ly blinking triangles in the display.
An active drift control increases the reproducibility of the measurements
as a constant condition is used to define the measured result. A smaller
value for the measuring parameter Drift requires a more stable measur-
ing signal than a larger one. The set measuring parameter is also pro-
portional to the measuring uncertainty of the measured value obtained.
Please note that the drift condition defined here and the temperature
parameter described below do not apply to the calibration of the direct
concentration measurement and, if necessary, must be set separately
under the calibration parameters (see Section 6.5.5).
temperature -999.9...25.0...999.9 °C
The correct recording of the measuring temperature is required for the
automatic correction of the electrode slope. If no temperature sensor is
connected you can enter the temperature of the solution under investi-
gation here. Information about the measuring temperature also makes
sense for the documentation of an ion-selective measurement. This
manually determined temperature is then indicated by the suffix ' manu-
al ' in the report header.
method 8 ASCII characters
All parameter settings can be stored together or loaded as a method
(see Section 6.1). The name of the current method is then given here.
This field is only used for information here and cannot be edited direct-
ly.
delta measurement: ON, OFF (only measurement type: direct)
The delta measurement permits the display of the measured value rela-
tive to a freely selectable constant reference value:
reference -1.00E+30...0.00...1.00E+30
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-
RAMETERS Conc/limits Conc ). The reference value is not included in
the report. However, should you still want to document it then you
should also 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-