3.15 ION SELECTIVE ELECTRODES - GOOD PRACTICE GUIDELINES
1.
Always start with the lowest concentration first if plotting a calibration curve.
2.
Wipe the membrane with tissue between measurements.
3.
Stir solutions wherever possible and ensure that all measurements are performed at a constant
temperature.
4.
Do not leave solid state electrodes in solution when not in use. Store safely to ensure the
electrode is not damaged.
For further details refer to the specific specification sheet supplied with the individual electrode.
3.16 CONCENTRATION MODE
Connect the electrode(s) and ATC probe(s) if used to the appropriate rear panel sockets.
Select the CONC mode using the arrow keys and press .
Select SETUP mode using the arrow keys and press .
EXIT
menu escape key
SLOPE
allows the sensor slope for the selected ion and channel to be changed
ISO-POTENTIAL
allows the sensor iso-potential for the selected ion and channel to be changed
REC O/P (1mV)
allows recorder output sensitivity to be entered. The value entered will give
a 1mV change in recorder output
ION
allows the ion selective electrode being used or channel using the arrow
keys This allows the instrument to check the sensor slope during calibration,
using the valency of the ion. Changes in display units will also correct all
displayed concentrations using the relative atomic/molecular mass for ion.
If the ion selective electrode used is not included on the instrument then
ION+, ION++, ION- or ION-- should be selected depending on the valency
of the ion
DISPLAY UNITS
allows selection of measurement unit appropriate to sample under test -
ppm, M, mg/l, Act, none, %
DISPLAY FORMAT
allows the format for concentration readings to be selected between integer
and exponential format. If set to integer, then readings will be displayed with
an exponent part if the reading is less than 0.001 or greater than 9999
CAL BUFFERS...
allows the calibration buffers for the selected mode and sensor input to be
viewed and changed
ALARM POINTS...
used to view and change alarm points for the selected mode and channel
INSTRUMENT SETUP...
used to select the next set up menu for instrument parameters
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