Thermo Scientific
On demand
Thermo Scientific Orion Star Conductivity/TDS/Salinity/Resistivity Portable Meter Kit, 2 models. Conductivity is the fastest way to ask how much is dissolved in
STARA2225
STARA3225
Thermo Scientific Orion Star Conductivity/TDS/Salinity/Resistivity Portable Meter Kit. Conductivity is the fastest way to ask how much is dissolved in a water without asking what.
The models differ by A222 and A322.
Conductivity, TDS, resistivity and salinity are the same measurement reported for four audiences. TDS is conductivity multiplied by a factor that depends on what is dissolved, so two meters set to different factors disagree on the same water — always record which factor was used. Resistivity is the reciprocal and is how ultrapure water is specified. Salinity is a conversion written for seawater.
Every conductivity cell has a constant that relates what it measures to what it reports, and that constant changes as the cell fouls, corrodes or gets scratched. Calibrating with a standard close to the value you will measure is the whole of good practice here: a cell calibrated at 1413 µS/cm and used on ultrapure water is calibrated for a different world.
Conductivity rises about 2% per degree, so a reading without temperature compensation is a reading of the room as much as of the water.
Supplied in 2 models.