[Solved] The most accurate method used in a laboratory for the determ (2024)

FAQs

[Solved] The most accurate method used in a laboratory for the determ? ›

Oven dry method is the most accurate and simplest method for water content determination.

Oven dry method is the most accurate and simplest method for water content determination. In this method complete drying of soil sample occurs and water content in the sample is calculated accurately by a maintained temperature in the oven ( 105°C to 110°C) for 24 hours.

The oven drying method is the most accurate method for the determination of water content of soil.

Pycnometer method is used to determine specific gravity and water content both. This method is suitable for cohesionless soils. Pycnometer is a glass jar of 1-liter capacity that is fitted at its top by a conical cap made of brass. It has a screw type cover and there is a small hole at its apex of 6 mm diameter.

The calcium carbide method is the quickest and reasonably accurate method of determining of the water content of soil using a portable moisture content kit. It usually requires 5 to 7 minutes for determining the water content.

The methods to determine moisture content in the laboratory are oven-drying, pycnometer, infrared lamp with torsion balance moisture meter. The approximate methods are alcohol burning method and calcium carbide method.

The accuracy of an analytical method is the degree of closeness between the 'true' value of analytes in the sample and the value determined by the method. Accuracy is often determined by measuring samples with known concentrations and comparing the measured values with the 'true' values.

The preferred method for determining soil moisture is the use of gravimetric soil moisture. However, if a person has experience in the hand-feel method and is comfortable in this method, this is an acceptable method.

Sand bath method

The sand is heated over a kerosene stove. The soil becomes dry within half to one hour. The water content can be determined by the formula. Higher temperature may break the crystalline structure of the soil, this method should not be used for Organic soils and soils having higher percentage of gypsum.

What is the laboratory method for determination of specific gravity? ›

Pycnometer Technique

It is a widely-used laboratory method for determining the specific gravity of soil. A pycnometer is a specialized glass or metal container equipped with a thermometer and a precisely fitted stopper through which air bubbles can be expelled using a vacuum pump.

Answer and Explanation:

Both the water displacement method and the Archimedes principle method can be accurate ways to determine the density of an object, but the water displacement method may be considered slightly more accurate in most cases so long as the density of the material is greater than that of water.

However, because the density of pure water is so close to 1 (0.9976 grams per cubic centimeter), specific gravity and density are nearly the same value so long as the density is given in g/cc. Density is very slightly less than specific gravity. Helmenstine, Anne Marie, Ph. D.

Calcium Carbide (Speedy Moisture) Test Procedure:

The calibration curve is established for each instrument using the general soil types to be tested. A range of soil samples of different material types and moisture content are selected and then carefully divided into two representative specimens.

The calcium carbide 'speedy' test helps us to determine the moisture content within a suspected damp wall. The test is more accurate than simply using a protimeter as conductive salts can produce false reading on electrical damp meters.

How is calcium carbide produced? Calcium carbide can be produced industrially from a mixture of lime and co*ke at about 2.200 ° C (3.990 ° F) in an electric arc furnace.

The most common method for water analysis is the Karl Fischer titration [65]. However, it tends to be labor-intensive and has multiple problems with many samples. The first requirement for water analysis is that a stationary phase retains water, and therefore it should be highly polar.

Two methods are available for the determination of water using the Karl Fischer method: a volumetric and a coulometric method. The method selected depends primarily on the amount of water to be determined. Volumetry: In the case of higher levels of water (0.1 – 100%), the volumetric method should be used.

The direct methods include mainly thermo gravimetric methods. The moisture content can be determined by an oven method directly. The food is weighed and dried, then weighed again according to standardized procedures. In the Thermogravimetric method, moisture is always separated.

Anhydrous C u S O 4 is used to test the presence of water in any liquid because it changes its colour from white to blue in the presence of water.