Yokogawa EXAxt SC450 4-Wire Analyzer for Conductivity/Resistivity - Manual (Page 61)

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APPENDICES
Appendix 4
Sensor selection for the EXAxt SC450G
Yokogawa supplies the following sensors, and their application is briefly described. All are compat-
ible with the EXAxt SC450G, and the user must be aware of the sensor configuration for 2 or 4
electrodes, in order to set the converter correctly.
SC42-SP34 (&SX42-SX34) cc = 0.01 cm -1 2-electrode sensor
This sensor is the first choice for pure and ultra pure water measurements. From 0.055µS/cm up to
100µS/cm this is a perfect choice. The measuring range extends to at least 1000µS/cm, but there
are better choices in that range.
Almost exclusively used in flow fittings and sub-assemblies. FF40 and FS40. (The -SX sensors are
screwed or flanged direct into the process pipework or tanks.)
SC4A-S(T)-XX-002...... cc = 0.02 cm -1 2-electrode sensor
This sensor is a good choice for pure and ultra pure water measurements. From 0.055µS/cm up
to 50µS/cm this is a good choice. The measuring range extends to 500µS/cm, but there are better
choices in that range. The “SC4A-” sensors make up a range that use compression adapters or
specialized fittings, including retractable.
SC42-SP24 (&SX42-SX24) cc = 0.1cm -1 2-electrode sensor
This sensor should be used for clean and pure water measurements. From 0.2µS/cm up to 1
mS/cm the sensor is fine, with measurement up to 10mS/cm possible, but there are better choices
in that range. Mounting of these sensors is as for the ....-SP(X)34 series.
SC4A-S(T)-XX-010...... cc = 0.1 cm -1 2-electrode sensor
This sensor is a good choice for clean water measurements. From 0.5µS/cm up to 200µS/cm this
is a good choice. The measuring range extends to 2000µS/cm, but there are better choices in that
range. The “SC4A-” sensors make up a range that uses compression adapters or specialized fit-
tings, including retractable.
SC42-EP15(D) cc = 1 cm -1 2-electrode sensor
This sensor is intended as a handy, short sensor. It is easy to fit in a branch (tee) on a pipeline,
and is good for measurements where the precision is less critical than a convenient installation.
The D version is particularly suited to food applications because of it’s cleanability. Range of ap-
plication is from 10µS/cm to 10mS/cm.
SC42-EP14 cc = 1 cm -1 2-electrode sensor
Clean cooling and process water applications are where this sensor is used. The best range of ap-
plication is 10µS/cm to 10mS/cm. It is better suited to flow through installations in FS40 and FF40
adapters and fittings, but it can also be used in dip tubes - FD40.
SC42-EP18 cc = 1 cm -1 4-electrode sensor
Cooling and process water applications are where this sensor is used, including light fouling. The
best range of application is 100µS/cm to 100mS/cm. The four-electrode system copes with some
contamination from the process, and eliminates the tendency for polarization to occur at the higher
conductivity. It is better suited to flow through installations in FS40 and FF40 adapters and fittings,
but it can also be used in dip tubes - FD40.