Hydrometer analysis is a laboratory method for determining the particle size distribution of soil. It involves the use of a hydrometer to measure the specific gravity of soil suspensions at various depths, and the results are then used to determine the particle size distribution.

Meniscus Correction:
- The meniscus is the curve at the surface of a liquid. When using a hydrometer, the meniscus can affect the accuracy of the readings.
- In hydrometer analysis, the meniscus correction is a positive correction, which means that it adds to the observed reading to correct for the meniscus.
- This is because the meniscus causes the surface of the liquid to curve upwards, which means that the hydrometer will appear to be floating higher than it actually is.
- Therefore, a correction is needed to adjust for this and obtain an accurate reading.

Dispersing Agent Correction:
- A dispersing agent is a chemical that is added to the soil suspension to prevent the particles from clumping together and settling out.
- In hydrometer analysis, the dispersing agent correction is a negative correction, which means that it subtracts from the observed reading to correct for the presence of the dispersing agent.
- This is because the dispersing agent can affect the specific gravity of the soil suspension, and therefore the observed reading on the hydrometer.
- The correction factor is determined by measuring the specific gravity of the dispersing agent and subtracting it from the observed specific gravity of the soil suspension.

In summary, the meniscus correction in hydrometer analysis is positive to correct for the curvature of the liquid surface, while the dispersing agent correction is negative to correct for the effect of the chemical on the specific gravity of the soil suspension.

As due to adding of dispersint agent ,density increases which leads to negative value for dispersing agent correction as also observed reading comes greater than true reading
and in Case of meniscus,the true reading is greater than the observed reading as taken at temperature greater than 27degree celsius