YOKOGAWA SC150, Instruction Manual

Page: 22 / 58

IM 12D7B4-E-H
16
Measurement Setup
Main parameter
Choose the required parameter, either
conductivity or resistivity. If the main
parameter is changed the instrument will
reset main display settings, units and
recalculate several values. The menu
structure will change accordingly.
5-1. Configure sensor
Sensor type
Choose the sensor type used. Normally
conductivity and/or resistivity
measurements are done with 2-electrode
type sensors. At high conductivity ranges,
polarisation of the electrodes may cause
an error in conductivity measurement. For
this reason 4-electrode type sensors may
be necessary.
Measuring unit /cm /m
Either /cm or /m can be chosen here. The
Process values will be expressed in S/cm
or S/m respectively, (
Ω
.cm or
Ω
.m in
Resistivity mode).
Cell constant (factory)
Cell constant given by factory calibration.
Usually given on a label on the sensor or
the calibration certificate.
Measure
Process values to be measured can be
selected to suit the user’s preference.:
Conductivity only, Concentration only or one
of both Conductivity and Concentration.
Note: this choice is not available in
Resistivity mode.
5-2. Temperature Setting
Temperature Element
Selection of the temperature sensor used
for compensation. The default selection is
the Pt1000 Ohm sensor, which gives
excellent precision with the two wire
connections used. The other options give
the flexibility to use a very wide range of
other conductivity/resistivity sensors.
Temperature Unit
Celcius or Fahrenheit temperature scales
can be selected to suit the user’s
preference.
5-3. Temperature Compensation
Compensation
Two types of methods can be used here.
Automatic for use of temperature element.
Select one of the Temperature elements
used. The other is a manual set
temperature. The manual temperature that
represents the process temperature must
be set here.
Reference Temperature
Choose a temperature to which the
measured conductivity (or resistivity) value
must be compensated. Normally 25°C
(77ºC) is used, therefore this temperature
is chosen as default value.
Method
TC In addition to the temperature
coefficient calibration routine it is possible
to adjust the compensation factor directly.
If the compensation factor of the sample
liquid is known from laboratory experiments
or has been previously determined, it can
be introduced here.
Adjust the value between 0.00 to 3.50 %
per °C. In combination with reference
temperature a linear compensation
function is obtained, suitable for all kinds of
chemical solutions.
NaCl Temperature compensation
according NaCl curve. See appendix 1 for
values.
Matrix The EXAxt is equipped with a
matrix type algorithm for accurate
temperature compensation in various
applications. Select the range as close as
possible to the actual
temperature/concentration range. The
EXAxt will compensate by interpolation. If
user defined 1 or user defined 2 is
selected, the temperature compensation
range for the adjustable matrix must be
defined.
See section 4-7 for matrix interpolation.
Note!
Extra information on temperature
compensation is given in appendix 1.