Thermo Fisher Scientific EcoScan CON 6 & TDS 6 - Manual (Page 50)

Instruction Manual CON 6/TDS 6
46
14 ADDENDUM 2: CALCULATING TDS CONVERSION
FACTOR
You can calibrate your meter using TDS calibration standard solutions. The
calibration standard only needs to give the TDS value at a standard
temperature such as 25 °C. To determine the conductivity-to-TDS conversion
factor use the following formula:
Factor = Actual TDS ÷ Actual Conductivity @ 25 °C
Definitions:
 Actual TDS: Value from the solution bottle label or as a
standard you make using high purity water and precisely
weighed salts.
 Actual Conductivity: Value measured using a properly
calibrated Conductivity/Temperature meter.
Both the Actual TDS and the Actual Conductivity values must be in the same
magnitude of units. For example, if the TDS value is in ppm the conductivity
value must be in µS; if the TDS value is in ppt the conductivity value must be in
mS.
Check your factor by multiplying the conductivity reading by the factor in the
above formula. The result should be in TDS value.