Total Dissolved Solids from Conductivity
Total dissolved solids estimated from a conductivity reading.
Example
You enter
- Conductivity (uS/cm at 25 C) 1000
- TDS/EC factor (0.4-0.9, default 0.65) 0.65
You get
- Total dissolved solids 650 mg/L
Checked against published worked examples from: Eutech Instruments (Thermo Fisher).
Details, formula, and sources
ScopeTDS (mg/L) = k x EC (uS/cm at 25 C), k commonly 0.55-0.75 (default 0.65). 1000 uS/cm -> 650 mg/L, with a 550-750 band from the k range so it is not read as exact. An estimate, not a gravimetric TDS; calibrate k to a lab result. The operator of record governs.
Formula or tabletds_mgl = k_factor x conductivity_us_cm; k commonly 0.55-0.75 (default 0.65).
Source and editionTotal dissolved solids from electrical conductivity (Standard Methods 2510), by name.
Free accessThe TDS = k x EC correlation is a standard published water-quality relation; the k factor is calibrated to the specific water.
What governsEstimate. Operator of record and primacy agency govern.
API field namesconductivity_us_cm, k_factor, tds_mgl
- Correlation TDS (mg/L) = k x EC (uS/cm at 25 C)Standard Methods 2510
- Factor range k commonly 0.55-0.75 by ion makeup; default 0.65water-quality practice
- Estimate not a gravimetric TDS; calibrate k to a lab resultscope of this tile