How To Calculate TDS

TDS Calculation Formula:

\[ TDS (mg/L) = Conductivity (\mu S/cm) \times 0.5-0.7 \]

Total Dissolved Solids (TDS):

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1. What Is TDS?

Total Dissolved Solids (TDS) refers to the total amount of mobile charged ions, including minerals, salts, or metals dissolved in a given volume of water. TDS is expressed in milligrams per liter (mg/L) or parts per million (ppm).

2. How Does The Calculator Work?

The calculator uses the TDS calculation formula:

\[ TDS (mg/L) = Conductivity (\mu S/cm) \times Conversion Factor \]

Where:

\( Conductivity \) — Electrical conductivity in microsiemens per centimeter (μS/cm)
\( Conversion Factor \) — Typically ranges from 0.5 to 0.7 depending on water composition

Explanation: The conversion factor varies based on the specific ionic composition of the water. For most natural waters, a factor of 0.67 is commonly used.

3. Importance Of TDS Measurement

Details: TDS measurement is crucial for assessing water quality, determining suitability for drinking, industrial processes, agriculture, and aquatic life. High TDS levels can affect taste, indicate contamination, or cause scaling in pipes and appliances.

4. Using The Calculator

Tips: Enter conductivity in μS/cm and select an appropriate conversion factor (0.5 for low mineral content, 0.7 for high mineral content, or 0.6 as a general average).

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between conductivity and TDS?
A: Conductivity measures water's ability to conduct electricity, which correlates with the concentration of dissolved ions. TDS is calculated from conductivity using a conversion factor.

Q2: What are acceptable TDS levels for drinking water?
A: The EPA recommends TDS levels below 500 mg/L for drinking water, though levels up to 1000 mg/L are generally acceptable.

Q3: Why does the conversion factor vary?
A: Different dissolved substances have different conductive properties. The factor depends on the specific ionic composition of the water sample.

Q4: Can TDS be measured directly?
A: Yes, TDS can be measured directly using TDS meters or calculated from conductivity measurements. Direct measurement provides more accurate results.

Q5: How does temperature affect conductivity measurements?
A: Conductivity increases with temperature. Most modern conductivity meters automatically compensate for temperature (ATC - Automatic Temperature Compensation).