Nova-Tech 2700 Series Benchtop Meters - Manual (Page 47)

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21. Calculating TDS Conversion Factor
You can calibrate TDS using the value of the calibration standard solution at a
standard temperature such as 25 ºC. To determine the conductivity-to-TDS
conversion factor use the following formula:
Factor = Actual TDS ÷ Actual Conductivity @ 25 ºC
• Actual TDS: Value from the solution bottle label or as a standard
made using high purity water and precisely weighed salts.
ppm = milligram of salt(s) per liter of water = mg/L
ppt = gram of salt(s) per liter of water = g/L
• 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.
When the TDS factor is set to 1.0, Conductivity = TDS.