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6. mV Calibration
The mV section is factory calibrated. There is no user-calibration facility for this
mode.
7. Relative mV Calibration
Select Relative mV mode when measurements relative to a known standard are
required. Calibration of the Relative mV mode is simply a matter of zeroing the
reading when the sensor is in the known standard.
1.
Plug the Redox sensor into the
Sensor
socket. Temperature compensation is
not applied in Relative mV mode, so the temperature sensor does not need to
be connected.
2.
Switch the meter on.
3.
Select Relative mV Mode (
→
→
F3:Mode
→
→
F4:Rel mV
).
The display should now be showing Relative mV on the top line with absolute
mV or date and time on the bottom line. For example…
1000mVR 25.0
O
c
500mV F4:Zeros
or:
1000mVR 25.0
O
c
31/12 12:00:00
Press
to alternate between absolute mV or the clock on the bottom line.
4.
Remove the wetting cap from the Redox sensor.
5.
Rinse the sensor in distilled water and blot dry.
6.
Place the Redox sensor into a sample of the known standard. Ensure that the
platinum tip and reference junction are both covered.
When the reading has stabilised, press the
key to zero the Relative mV
reading. The Relative mV reading will now be zero, and the absolute mV
reading will remain unchanged. For example…
0mVR 25.0
O
c
500mV F4:Zeros
or:
0mVR 25.0
O
c
31/12 12:00:00
7.
The
WP-90
Relative mV mode is now zeroed and is ready for use. The
readout can be re-zeroed by pressing the
key whenever required.
7.1 Notes
1.
The Relative mV offset is retained in memory when the
WP-90
is switched
off, even when the battery is removed.
2.
The Relative mV zero is reset when leaving Relative mV mode.