Importance of Representative Sample and Sample Divider

We receive a lot of foodgrains into our Grain Terminal, Rice Mills Flour Mills and Dal Mills in Bulk form and Bagged form. Grain receiving is a very important activity in any grain business whether storage or milling as profitability of the grain business depend solely on this activity. Receiving a good quality food grain means longer storability, far better milling yield, and minimum expenses on fumigation, aeration and ventilation, de-coring, and cleaning. In a nutshell, you save a lot.

Grain quality assessment plays a very important role in ensuring that you receive only good quality grain. One should have well defined Standard Operating Procedures to access the Grain Quality while receiving the grain. In India I have seen many people bypassing standard operating procedures to access grain quality. And in most cases that I came across, I saw people not giving due importance to Representative Sampling fundamentals which results in incorrect grain sample analysis and results in huge business losses.

Representative Sampling Representative sample is the first stage of Grain Quality Assessment. Representative Sample means a sample that represent the entire grain bulk which is being assessed for quality. If we follow the Representative Sample fundamentals, we can determine the quality of entire lot of grain bulk being assessed with a very high accuracy. There are two very important stages of Representative Sampling. 1. Drawing samples on random basis from various locations of a grain bulk and mixing them together to form a homogeneous sample 2. Dividing this homogenous composite sample into two or more representative samples to initiate quality analysis Samples are collected from Bagged / Bulk vehicles using Hand Probes, Double Sleeve type Triers, Hydraulic Truck Sampling Probes, Hand Scoops, Automatic Screw samplers etc. Samples are collected on random basis from 5-6 locations from a bulk lot and approximately from 10% bags from a bagged lot. Once the sample is drawn from various locations or bags, it is mixed to form a homogeneous mixture and this mixture is called a Composite Sample. You may analyse this sample to assess the quality of grain bulk contained in the vehicle, for parameters like moisture, dockage, weight per thousand grains etc. but this will delay lab analysis as one sample will move from one machine to another. In order to save time and expedite declaration of sample result this composite sample is divided into two or more representative samples. A composite sample when reaches a grain quality lab, it is divided into two or more parts to represent composite sample as a whole so that 2-3 tests can be conducted on composite sample simultaneously like moisture percentage test, dockage test, weight per thousand grains test etc. If we want the analysis results to be accurate then the division of a composite sample into two or multiple samples is highly important otherwise you will never get accurate results.

“YOU MUST NEVER DIVIDE A SAMPLE INTO TWO OR MORE MANUALLY”

When you divide a sample manually it will never lose its representativeness of grain lot and will never give you correct results. Hence scientific division of a composite sample into two or more must be carried out to get accurate quality analysis results. There are two sample dividers that give very accurate results are Boerner Divider and Gamet Centrifugal Divider. They are known to split a composite gain sample with an accuracy of +/-1% which is a fairly high accuracy. Manually division will never give you this accuracy.

Boerner Divider Boerner Divider is a part of grain industry since its inception and one of my favorite sample divider. Boerner Divider is an apparatus that divides a composite sample into two equal representative samples with gravity. The Boerner Divider is calibrated to provide accurate splits of + /– 1% on a 1000g sample. Boerner divider is made from brass and copper, which makes it rust resistant. The legs and supports are powder coated mild steel. Entire bottom section is removable to facilitate cleaning whenever necessary.