Yokogawa EXAxt SC450 4-Wire Analyzer for Conductivity/Resistivity - Manual (Page 28)

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IM 12D08N05-01E
Measurement setup
Main parameter
Choose the required parameter, either con-
ductivity 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, polarization 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 proc-
ess 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. Only change this value
in case a new sensor is used. By changing this
value the actual cell constant is also changed.
Measure
Process values to be measured can be se-
lected to suit the user’s preference.: Conduc-
tivity 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.
When the unit is changed all temperature
related parameters and settings will be recal-
culated.
5-3. Temperature compensation
Compensation
Two types of methods can be used here. Au-
tomatic 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 tem-
perature must be set here.
Reference Temperature
Choose a temperature to which the meas-
ured conductivity (or resistivity) value must be
compensated. Normally 25°C (77ºF) is used,
therefore this temperature is chosen as the
default value.
Method
TC In addition to the temperature coefficient
calibration routine it is possible to adjust the
compensation factor directly. If the compensa-
tion 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 ma-
trix 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 Appendix 1 for matrix interpolation.
Note! Extra information on temperature
compensation is given in Appendix 1.
5. MENU STRUCTURE COMMISSIONING