Density Measurement Test Laboratory

Density Measurement Test Laboratory

Density measurement, which is an important quality parameter for raw and finished products in solid and liquid conditions, is done by various techniques. Particularly, the density measurement which is important in determining the purity of the materials before processing is important in determining whether a substance is mixed with the raw material. On the other hand, this study is effective in understanding the homogeneity of the raw material. Samples taken randomly from the processed product are tested. The purpose of these tests is to monitor the continuity of quality. The random sample selection process for quality monitoring is one of the most basic and cost-effective methods.

We can summarize the fact that the density test is cheap and that it uses water removal method. In other words, this method, called gravimetric, utilizes the simple lifting force of water. It consists of a combination of lifting force technique, displacement principle and pycnometer methods. Accurate measurement of density measurement is very important for weighing. In its simplest terms, according to the principle of Archimedes, when an object is immersed in a liquid, it is subjected to a buoyant force by the liquid, and also the object is displaced by a certain proportion of the liquid. The calculation of this displacement is equivalent to the density of the object. In the calculation process, variables such as weight of object, volume of displaced liquid and density of liquid are considered.

Methods used in determination of density and its distinctive features

methods

Gravimetric, Lifting Force

Gravimetric, Displacement

Pyknometer

Digital Density Meter

       

The container with the liquid used in the density measurement is located under the platform or the scale

Fluid used to measure density stops at scale

Cap with a defined volume

Oscillation tube technology

Available fields

- Solid

- Liquid (glass kit to be used must be standard weight)

- Paste materials (gamma spheres)

- Liquids (the glass kit to be used must be of standard weight)

- Solids

- Liquids, distributions

- Powder

- Particles

- Liquids

- Gases

Benefits

- Fast processing process

- Flexibility in sample size

- Weighing device is in use

- Fast processing process

- Weighing device is in use

- The correct method

- Weighing device is in use

- Fast processing process

- Precise control of temperature with Peltier elements

- Automatic density measurement

- Small sample volumes

Drawbacks

- Temperature sensitive

- Need to be placed very carefully

- Temperature sensitive

- Large sample volume requirement

- Temperature sensitive

- Troublesome

- Time-consuming

- The need to remove air bubbles

- Viscosity correction requirement in adhesive samples (available in modern devices)

 

Standards and standards used in calculation of density

ISO 1183-1: Plastics - Methods for determining the density of non-cellular plastics

OIML G 14: Density measurement according to OIML

ASTM-D-792: Standard Test Methods for Density and Specific Gravity Standard

ISO 1183-1 indicates that an 4 analytical balance with a decimal digit must be used.

The particle contained in a given volume corresponds to the measurement bulk density, which depends on the number of parts it contains. The Density feature is a distinguishing feature for all substances found in the real world. Density measurement for raw and finished products is used as a quality parameter which is extremely important. There are many parameters that must be considered in order to determine the exact density. The most important measurement tools we can recommend for density measurement are scale and density kit.

The most important error in the determination of density is the limited wetting of the raw material or product during the measurement. In other words, the presence of air bubbles adhering to the walls of the sample or the device when density is performed is the most important factor that puts the measurement at risk. Reducing air bubbles to zero is also an indicator of the reliability of the test. Otherwise, the presence of air bubbles results in extra buoyancy, which in turn destroys the density calculation. Assuming that any air bubbles in the wall of the tested object or container are in the 1 mm age, this air bubble generates a lifting force of 0.5 mg. Things to do;

  • Use of wetting agent or organic liquids to remove air bubbles. A few drops of wetting agent used due to the pretreatment to be ignored for density testing, is not to be ignored.
  • Solvent-resistant solids must be removed completely.
  • All equipment under test must be cleaned regularly.
  • The object to be immersed in the liquid should not be touched with bare hands in any way.
  • A thin brush is required to remove stubborn air bubbles.

Factors affecting density

  • Temperature: substances in different phases show different sensitivity to temperature. The temperature is usually the least effect on the density properties of solids. Changes that may occur as a result of temperature fluctuations have no effect on the density of solids. However, the temperature has a greater effect on the liquid materials, such that the concentration of 0,1% - 1% at each degree of density in the liquid substance to be used in measuring the density of the solids occurs. This also increases the margin of error with the expanded fluid. The margin of error in the measurement causes a significant change in the third decimal point of the result. The temperature of the liquids to be used in the density measurements must always be taken into account in order to obtain the correct result in terms of quality. The most important reference liquids used for density determination of solids are Water or Ethanol.
  • Weighing: it is important to accurately determine the weighing density, and therefore it is of particular importance that the balance used to meet the density application requirements. If the sample is a small sample, the minimum net weight of the balance must be taken into account. Accurate results are obtained if reference is made to the minimum net weight, otherwise the results are unreliable in the measurement of small samples.
  • Data Usage: The manual recording of the values ​​to be used in the calculation during the density determination of the sample takes time and increases the risk of error.

METTLER TOLEDO method for density determination

This study is carried out by using scales with precision at 1mg in precision scales. With several density kits to be used on high precision scales, the buoyancy of the liquid is calculated in a few simple steps. After the calculation, the density is obtained at the level of milligrams and a more significant value is obtained.

This method is used for the other density determination of the largest of different precision scales is the measurement of the level of milligrams. In this method, the volume of the part is determined independently of its weight, and as a result of the calculations, calculating the overflowing fluid volume and weight values ​​help to obtain the most reliable result.

These operations stand out in terms of being both simple and easy. There is no need to purchase special equipment or parts to add a density kit to a standard laboratory balance. On the contrary, purchasing a few low-cost density kit accessories will help turn your precision balance into a density determination tool. A glass of known volume is added to the density kit to be used and the density of the samples is determined with the liquid you will use in this glass apparatus with standard weight.