Nova-Tech pH 700 Ion 700 - Manual (Page 8)

3.3 Millivolt (mV) Offset Adjustment
Oxidization Reduction Potential (ORP or Redox) is not a precise
measurement, but is useful as a relative indicator. As such, mV offset
adjustment is not meant to enhance accuracy, but rather to make readings
comparable to a reference. Commercial ORP solutions are often used as
a check standard in which a meter/electrode system are verified to be
close to a given value, instead of being used as a calibration standard in
which adjustments are made in an attempt to match the ORP value.
1) Connect an ORP electrode and press as needed to select mV
(or R.mV).
2) Dip the ORP electrode into a solution with a known mV value
(i.e. Zobel, Light’s, quinhydrone, or iodidetriiodide) and stir.
3) Press when the reading is stable. The primary display shows the
relative millivolt value (R.mV) while the secondary display shows the
factory default mV value.
4) Adjust the R.mV value using or . Press to accept or to
cancel. The meter allows an adjustable maximum value of ± 150 mV
from the factory default mV value.
Note: When an offset has been stored successfully, R.mV replaces mV.
3.4 Ion Calibration (Ion 700 Only)
The Ion 700 can measure ion concentration such as ammonia or fluoride
when using an ion selective electrode (ISE) for the specific ion of interest.
The available ion calibration values are 0.10, 1.0, 10.0, 100.0, and 1000
parts per million (ppm). Choose a minimum of 2 consecutive values for
calibration and prepare the corresponding ion calibration solutions. For
best results always begin with your lowest standard value, followed by
the next lowest standard.
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