1. What is the Langelier Saturation Index?

The Langelier Saturation Index (LSI) is a calculated number used to determine the calcium carbonate stability of water. It indicates whether water will precipitate, dissolve, or be in equilibrium with calcium carbonate.

2. How Does the Calculator Work?

The calculator uses the LSI formula:

Where:

• \( pH \) — pH value (dimensionless)
• \( TF \) — Temperature Factor
• \( CF \) — Calcium Factor
• \( AF \) — Alkalinity Factor

Explanation: The equation calculates the saturation level of calcium carbonate in water, helping predict scaling or corrosive tendencies.

3. Importance of LSI Calculation

Details: LSI is crucial for water treatment, pool maintenance, and industrial processes to prevent scaling in pipes and equipment or corrosive damage to infrastructure.

4. Using the Calculator

Tips: Enter pH value (dimensionless), temperature factor, calcium factor, and alkalinity factor. All values must be valid numerical inputs.

5. Frequently Asked Questions (FAQ)

Q1: What does a positive LSI value indicate?
A: A positive LSI indicates scaling tendency - water is supersaturated with calcium carbonate and likely to form scale.

Q2: What does a negative LSI value indicate?
A: A negative LSI indicates corrosive tendency - water is undersaturated and will dissolve calcium carbonate.

Q3: What is the ideal LSI range?
A: For most applications, an LSI between -0.3 and +0.3 is considered balanced, indicating neither significant scaling nor corrosion.

Q4: How are the factors (TF, CF, AF) determined?
A: These factors are derived from water temperature, calcium hardness, and total alkalinity measurements using standard conversion tables or formulas.

Q5: Where is LSI commonly used?
A: LSI is widely used in swimming pool maintenance, cooling tower operation, boiler water treatment, and drinking water distribution systems.