Astm D 4373 -

A calibrated manometric or volumetric device (typically a or similar gas-measuring apparatus) measures the pressure or volume of CO₂ evolved. This measurement is directly proportional to the CaCO₃ content, which is expressed as a percentage of the dry soil mass.

[ \textCarbonate (%) = \frac\textCO_2 \text pressure/volume reading\textDry soil mass \times \textCalibration factor ]

Or directly from a pre-established calibration curve using pure CaCO₃. astm d 4373

This test method covers the quantitative determination of the carbonate content (primarily calcium carbonate, CaCO₃) in soils, using a gasometric method. It is suitable for both fine-grained and coarse-grained soils, as well as soft rock and aggregate materials.

| Step | Action | |------|--------| | 1 | Dry the soil sample at 105°C to a constant mass. | | 2 | Crush soil to pass a No. 200 (75 µm) sieve. | | 3 | Weigh a specimen (typically 1–10 g, depending on expected carbonate content). | | 4 | Place specimen into the reaction vessel. | | 5 | Add HCl (without allowing contact until sealed) into a separate chamber or capsule within the vessel. | | 6 | Seal the gas-measuring apparatus. | | 7 | Tip the apparatus to allow acid to contact the soil. | | 8 | Record the maximum gas pressure or volume reading after reaction stabilizes (usually 1–2 minutes). | A calibrated manometric or volumetric device (typically a

Method: ASTM D4373 – 2021 Analyst: [Name] Date: [Current Date]

The method relies on the chemical reaction between carbonates present in the soil and hydrochloric acid (HCl). The reaction produces carbon dioxide (CO₂) gas. This test method covers the quantitative determination of

D4373 – 14 (or current active version: 2021)