User guide

54
IM 12D08N05-01E
SC42-EP04 cc = 10 cm
-1
2-electrode sensor
This sensor is in the program for historical reasons. It makes little sense to select this sensor for
new applications.
It was used mostly for process water and light process solutions. The operating range can be 1to
100 mS/cmwith higher readings having a very high risk of polarization.The SC42-EP18 or the
SC42-EP08(4-elsensors)coverstheserangeswithmuchgreatercertaintyofavoidingpolariza-
tion.
SC42-EP08 cc = 10 cm
-1
4-electrode sensor
Process applications are where this sensor is used, including light fouling. The best range of ap-
plicationis1mS/cmto500mS/cm.Thefour-electrodesystemcopeswithsomecontaminationfrom
the process, and eliminates the tendency for polarization to occur at the higher conductivity. The
upper limit is determined more often by chemical compatibility. The epoxy material is attacked
by many of the chemicals that are present in high conductivity solutions. 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-TP08 (FP08) cc = 10 cm
-1
4-electrode sensor
Thesesensorsareforextremeapplications.ThePTFEorthePVDFusedforthebodyofthesen-
sor gives good chemical resistance for the strongly corrosive applications. These sensors are
intended for usein ranges 10mSto 1000mS/cm. Carefulselection of theholder is needed.The
PVDFsub-assemblyisanobviouschoicefortheSC42-FP08,andthePPflowfittingoftenhassuf-
ficient corrosion resistance for the application. In any case selection must be done with due regard
to the process conditions.
The 2-electrodeversions (SC42-T(F)P04 do exist, but like the epoxy version (SC42-EP04) they
should be discounted for new applications.