Determination of Grain Bulk Density

Determination of Grain Bulk Density

Overview

  Grain bulk density refers to the mass of grain per unit volume in its natural state, expressed in grams per liter (g/L). It serves as a core indicator for grading grain, evaluating grain quality and kernel plumpness, and directly reflects the kernel density, plumpness and uniformity of grain. Bulk density is adopted as one of the key judgment criteria for the grade classification of various grains including wheat, corn, legumes and millet. Accurate determination of grain bulk density is of great practical guiding significance for grain purchasing, storage, processing and trade pricing.

Experimental Purpose

  By testing the bulk density value of grain, its quality grade and kernel plumpness can be accurately determined, so as to provide scientific data support for grain purchasing, storage grading and processing screening. This grain bulk density determination is conducted in accordance with the relevant standard methods for grain quality inspection. The ST128 Electronic Bulk Density Meter is a professional instrument specially designed for grain bulk density testing, which is applicable to the bulk density measurement of small-particle grains (wheat, millet) and large-particle grains (corn, legumes), meeting the professional requirements of grain inspection.

Experimental Samples and Instruments

Experimental Sample: Wheat (replaceable with corn, legumes, millet and other grains)

Experimental Instruments:

• ST128 Electronic Bulk Density Meter
• Auxiliary tools such as sample leveling implement

Operating Procedures

1. Connect the power supply of the ST128 Electronic Bulk Density Meter and turn on the power switch at the rear of the cabinet. Press the Zero key to reset the display to zero. Place the volume cylinder and exhaust hammer on the pan of the electronic scale, press the Tare key to complete the taring operation, and then remove them.
2. Mount the volume cylinder on the plastic base and place it on a horizontal workbench, insert the insert plate, place the exhaust hammer flat, and fit the middle cylinder in position; pour the prepared grain sample into the grain cylinder, fill it up and level it off, then fit the grain cylinder onto the middle cylinder.
3. Open the hopper switch to allow the grain to fall freely. After all the samples have fallen into the volume cylinder, close the switch and pull out the insert piece quickly. After the exhaust hammer and samples settle down, reinsert the insert plate, and remove the grain cylinder and the middle cylinder in sequence.
4. Pour off the excess sample on the insert piece of the volume cylinder, pull out the insert piece, and place the volume cylinder stably on the electronic scale. After the weight is stabilized (the word Stable is displayed on the left side of the screen), read the value. If the test result needs to be saved, press the Print key to print the detection data.
5. For continuous testing of multiple groups of samples, press the Zero key to reset the display to zero, and then repeat the above steps to complete the subsequent measurements.

Note: When measuring large-particle grains such as corn and legumes, remove the hopper slider; when measuring small-particle grains such as wheat and millet, install the hopper slider in position before the test.

Data Analysis and Result Evaluation

  The bulk density of the wheat sample tested by the ST128 Electronic Bulk Density Meter is 780 g/L, which meets the national grade standard for high-quality wheat (bulk density ≥750 g/L). The instrument has a measurement division value of 1 g and a volume cylinder volume accuracy of 1000±1.5 ml, with the detection error controlled within the allowable range specified in the grain bulk density testing standards, featuring accurate data and good repeatability. The results of multiple repeated tests on large-particle grains such as corn and legumes show that the instrument has small measurement deviation, is suitable for the bulk density testing of grains with different particle sizes, and is characterized by easy operation and reliable results. It can meet the requirements of batch and rapid determination in grain purchasing, storage inspection and other application scenarios.