Six ranges of conductivity are possible and are selected automatically. Readings are displayed in multiples of S/em or S/m. One of the main sources of error when measuring conductivity arises from polarisation effects at the cell plate surfaces. The measuring frequency of the FE287 is such that polarisation effects are minimised but it is important to choose the cell type most appropriate to the expected conductivity. In addition, any nonlinearity arising from polarisation may be corrected for when using the FE287 by entering up to four calibration points. This will lead to increased accuracy over the range of the selected cell. Measuring ranges for particular cell types are given on the back of the brochure.
Resistivity
The reciprocal of conductivity, it is possible to display resistivity in either M0 cm or MO m.
TDS
Total dissolved solids TDS) is related to conductivity and is measured simply by switching to the TDS mode and reading directly in mg/L.
Concentration
One of the most common applications of conductivity measurement is concentration control. The FE287 can be calibrated in concentration units and samples then read directly in the units chosen, making it an extremely useful quality control instrument.
Salinity
The FE287 automatically converts from conductivity to salinity using the correct non-linear temperature relationship for sea water. This is in accordance with recommendations made by UNESCO, IASPO.
Temperature
All cells contain a thermistor for temperature measurement and compensation. All measurements ace referenced to 250C. With the FE287 it is possible to determine and enter temperature coefficients for different electrolytes for increased accuracy. Temperature can also be read directly in degrees Celsius or Farenheit.