 
  
 ICS 65.060.01  
 
Reference number  
DRS  269-5:2020  
© RSB 2020  
  
 RWANDA 
STANDARD  DRS  
269-5:2020  
 
2nd edition  
2020 -June  
 
Agroprocessing  machine s — Test 
methods —  
 
Part 5: Maize  mill 
   
DRS  269-5:2020  
©RSB 2020 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB2020  
All rights reserved. Unless  otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce thi s document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS  269-5:2020  
iii                ©RSB2020 - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 General conditions for test and inspection  ................................ ................................ ........................  2 
4.1 Role of manufacturer/dealer  ................................ ................................ ................................ .................  2 
4.2 Test site conditions  ................................ ................................ ................................ ...............................  2 
5 Suspension of test  ................................ ................................ ................................ ................................  2 
6 Test preparation  ................................ ................................ ................................ ................................ .... 2 
6.1 Preparation of the maize mill for testing  ................................ ................................ .............................  2 
6.2 Test materials  ................................ ................................ ................................ ................................ ........  2 
6.3 Running -in and preliminary adjustments  ................................ ................................ ...........................  2 
7 Pre-test observation  ................................ ................................ ................................ ..............................  3 
8 Performanc e test  ................................ ................................ ................................ ................................ ... 3 
8.1 Operation of the maize mill  ................................ ................................ ................................ ..................  3 
9 Sampling  ................................ ................................ ................................ ................................ ................  3 
9.1 Procedure  ................................ ................................ ................................ ................................ ...............  3 
9.2 Data collection  ................................ ................................ ................................ ................................ ....... 3 
9.2.1  Duration of test  ................................ ................................ ................................ ................................ ...... 3 
9.2.2  Noise level  ................................ ................................ ................................ ................................ ..............  3 
9.2.3  Energy consumption  ................................ ................................ ................................ .............................  4 
9.2.4  Data recording and observations  ................................ ................................ ................................ ........  4 
10 Laboratory analysis  ................................ ................................ ................................ ...............................  4 
11 Formula  ................................ ................................ ................................ ................................ ..................  4 
12 Test report  ................................ ................................ ................................ ................................ ..............  4 
Annex  A (normative)  Test materials for maize mill  ................................ ................................ ........................  5 
A.1 Sample characteristics  ................................ ................................ ................................ ................................  5 
A.2 Quantity to be supplied  ................................ ................................ ................................ ...............................  5 
A.3 Sample preparation  ................................ ................................ ................................ ................................ ..... 5 
Annex  B (nor mative)  Specification for maize mill  ................................ ................................ ..........................  6 
Annex  C (normative)  Sampling and measurements for test material  ................................ ......................  910 
C.1 Sampling from different outlets  ................................ ................................ ................................ ....... 910 
C.2 Handling of samples  ................................ ................................ ................................ ................................  910 
C.2 Other measurements required during the test run  ................................ ................................ ........  910 
C.3 Measurement of fuel consumption  ................................ ................................ ................................ .. 910 
C.4.1 For maize mill using engine as prime mover  ................................ ................................ .....................  910 
12.1.1  C.4.2 Using electric motors as prime mover  ................................ ................................ ................  1011 
Annex  D (normative)  Performance test data sheet  ................................ ................................ ..................  1112 DRS  269-5:2020  
©RSB 2020 - All rights reserved                  iv 
 Annex  E (normative)  Laboratory analysis  ................................ ................................ ................................  1517 
E.1 Purity determination  ................................ ................................ ................................ .......................  1517 
E.2 Moisture content  ................................ ................................ ................................ .............................  1517 
E.3 Analysis of output from degerminator to determine the degerminator efficiency  ..................  1517 
E.4 Analysis of main products  ................................ ................................ ................................ .............  1517 
E.5 Analysis of by -products  ................................ ................................ ................................ .................  1517 
E.6 Analysis of output from roller mill to compare laboratory result with machine’s output  ....... 1618 
Annex  F (normative)  Laboratory test data sheet  ................................ ................................ .....................  1719 
12.2  F.1 Moisture content determination  ................................ ................................ ..............................  1719 
12.3  F.2 Purity determination (500 g sample)  ................................ ................................ ......................  1719 
Annex  G (normative)  Formula used during c alculations and testing  ................................ ...................  2022 
 DRS  269-5:2020  
v                ©RSB2020 - All rights reserved  
 Foreword  
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards 
adop ted by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
DRS  269-5 was prepared by Technical Committee RSB/TC 47, Steel, aluminium and related products.  
In the preparation of this standard, reference was made to the following standard  (s): 
1) XYZ: Title  
2) XYZ:Title  
The assistance de rived from the above source is hereby acknowledged with thanks.  
This second  edition cancels and replaces the first  edition (RS  269-5:2015 ) which has been tech nically revised.  
DRS  269 consists of the following parts, under the general title Agricultural machinery — Test methods : 
 Part 1: rice thresher  
 Part 2: Power operated maize sheller  
Part 3: Rice mill  
 Part 4: Heated air mechanical grain dryer  
 Part 5: Maize mill 
Committee membership  
The following organizations were represented on the Technical Committee on Steel, aluminium and related 
products  (RSB/TC 47 ) in the preparation of this standard.  
University of Rwanda/college of science and technology  
University o f Rwanda/College of agriculture animal science and veterinary medicine  DRS  269-5:2020  
©RSB 2020 - All rights reserved                  vi 
 Kabizu business group  
Rwanda Polytechnic/IPRC Kigali  
Rwanda Polytechnic/IPRC Ngoma  
Rwanda Polytechnic/IPRC Musanze  
RWANTECH Boilers  
Rwanda Inspectorate and competition authority  
Rwanda Institute for Conservation Agriculture  
ACER Ltd  
 Rwanda Standards Board (RSB) – Secretariat  
  DRS  269-5:2020  
1                ©RSB2020 - All rights reserved  
 Agroprocessing machines — Test methods — Part 5: Maize  mill 
1 Scope  
This Draft Rwanda Standard specifies the methods of sampling, testing and inspection for maize mill.  
2 Normative references  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document.  For dated references, only the edition  cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies.  
RS 268 -5, Agroprocessing machines  — Specification — Part 5: Maize mill    
RS 241, Agriculture machine ry — Methods of sampling  
3 Terms and definitions  
For the purposes of this document, the terms and definitions given in  RS 268 -5 apply.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— IEC Electropedia: available at http://www.electropedia.org/  
— ISO Online browsing platform: available at http://www.iso.org/ob p 
3.1 
degerminated maize kernels  
shelled maize kernels where the germ  and pericarp have been removed  
3.2 
feed rate  
weight of the maize kernels fed into the maize mill per unit of time  
3.3 
laboratory sieve shaker  
equipment with definite shaking motion used to sort the size of the milled materia ls using standard screen 
sieves   
©RSB 2020 - All rights reserved                  2 
 3.4 
Purity  
ratio of the weight of clean maize kernels, to the total weight of uncleaned maize kernels, expressed in 
percent  
4 General conditions for test and inspection  
4.1 Role of manufacture r/dealer  
The manufacturer/dealer shall comply with the test procedures of national testing authority.  
4.2 Test site conditions  
The maize mill shall be tested as installed for normal operation. The site shall have ample provisions for grain 
handling, temporary  storage and workspace.  
5 Suspension of test  
5.1 If during the test run, the machine stops due to breakdown or malfunction so as to affect the machine’s 
performance, the test may be suspended.   
5.2 The decision to  suspend or to continue the test is at the discretion of the test engineer and concurred by 
the representative.  
6 Test preparation  
6.1 Preparation of the maize mill for testing  
6.1.1  A check shall be made by the manufacturer/client and testing authority that the maize mill has been 
assembled and install ed in accordance with the instruction of the manufacturer.  
6.1.2  The maize mill shall be cleaned adequately for the purpose of testing.  
6.2 Test materials  
The maize kernels to be used for testing shall be of the same grade and prepared in sufficient quantity, 
using the procedure given in Annex A.   
6.3 Running -in and preliminary adjustments  
6.3.1  Before the start of the test, the maize mill shall have undergone a breaking -in period.   
6.3.2  The maize mill shall be operated at the test site for sufficient duration with and without load.   DRS  269-5:2020  
3                ©RSB2020 - All rights reserved  
 6.3.3  During the running -in period, the various adjustments of the maize mill shall be made according to the 
manufacturer’s rec ommendations.   
6.3.4  No other adjustments shal l be permitted during the test.  
7 Pre-test observation  
The specifications claimed by the manufacturer and the physical details given in Annex B shall be verified by 
the recognized testing authority.  
8 Performance test  
8.1 Operation of the maize mill  
8.1.1  The maize mill shall be operated at the manufacturer’s recommended setting of its components.  
8.1.2  The recommended feeding rate shall be maintained during the test run with duration of at least one 
hour.    
8.1.3  After the test -run, the milling area shall be cleaned and then prepared for the next test trial(s).   
8.1.4  This procedure shall be repeated for at least three test trial(s).  
9 Sampling  
9.1 Procedure  
Sampling procedure is given in Annex C.  
9.2 Data collec tion 
9.2.1  Duration of test  
The duration of each test trial shall start with the feeding of the maize kernels into the intake hopper/intake pit 
and ends after the last discharge from the main output chute.  
9.2.2  Noise level  
9.2.2.1  The noise emitted by the machine, with or without load, shall be measured using a noise level 
meter at the location of the operators and baggers.   
9.2.2.2  The noise limit shall comply with the requirements specified in RS 236  
9.2.3 Speed of components   
©RSB 2020 - All rights reserved                  4 
 The speed of the rotating shafts of the major components of the maize mill shall be taken using a tachometer. 
Measurements shall be taken with and without load for 9.2.2 and 7.1.3 as specified in Annex D  
9.2.3  Energy consumption  
9.1.4.1  Before the start of each test trial, the fuel tank shall be filled to its capacity and after each test; the 
fuel consumed shall be measured.   
9.1.4.2  In case an electric motor is used as a prime mover, a power meter shall be used to measure 
electric energy consumption.  
9.2.4  Data reco rding and observations  
Record sheet for all data and information during the test is given in Annex D. Observations to be taken 
during the performance test shall be recorded.  
10 Laboratory analysis  
10.1 The analysis is carried out to analyze the kernel sample s taken during the performance test.   
10.2 The laboratory procedures to be followed in the analysis are given in Annex E and the data sheet to be 
used is given in Annex F.  
10.3  The percentage of maize grits of other sizes from each outlet shall be determ ined using a laboratory 
sieve shaker with sieves of the same sizes as in the maize mill.  
11 Formula  
The formula to be used during calculations and testing are given in Annex G.  
12 Test report  
The test report shall include the following information:  
a) title;  
b) summary of results;  
c) purpose and scope of Test;  
d) methods of Test;  
e) conditions of the machine;  
f) description of the machine;  
g) results and discussions;  
h) observations (include pictures); and  
i) names and signatures of test engineers  
 DRS  269-5:2020  
5                ©RSB2020 - All rights reserved  
 Annex  A 
(normative)  
 
Test materials for maize  mill 
A.1 Sample characteristics  
Test materials to be used shall have the following characteristics:  
a) variety : hybrid  
b) grain moisture content : dried to uniform moisture content of 13.5 %  
c) purity , percent, minimum: 95  
A.2 Quantity to be supplied  
A.2.1  The amount of test material to be supplied shall be sufficient for at least 3 h 30 min of continuous 
milling operation.   
A.2.2  At least three test trials shall be conducted with minimum duration of 1 h per trial. The excess 
amount shall be used for running -in prior to the actual conduct of test trials.  
 A.2.3  Approximately: 2.5 h x milling capacity (t/h)  
A.3 Sample preparation  
Prepare the sample in such a way that test sample to be used for the running -in and in each test trial 
shall have identical  characteristics in terms of moisture content, purity and variety.   
©RSB 2020 - All rights reserved                  6 
 Annex  B 
(normative)  
 
Specification for maize  mill 
Name of Applicant (Distributor): _______________________________________________  
Address: _______________________________________________________ ___________  
Tel No: ___________________________________________________________________  
Manufacturer Name : ________________________________________________________  
Address: 
__________________________________________________________________ Tel 
No: ____ _______________________________________________________________  
Address: __________________________________________________________________  
GENERAL INFORMATION  
Serial No: ______________________ Brand/Model: _______________________________  
Type: ______________________ Make: _______________________________  
Production date of maize mill to be tested: _______________________________________  
Testing agency: _________________ Date of testing: ______________________________  
Location of test: __ ________________ Test Engineer: ______________________________  
Table B 1 — Items to be inspected  
Items  Manufacturer’s 
Specifications  Verification by the Testing 
Agency  
B.1 Main Structure    
B.1.1 Overall dimensions (mm)    
B.1.1.1 length    
B.1.1.2 width    DRS  269-5:2020  
7                ©RSB2020 - All rights reserved  
 B.1.1.3 height    
B.1.2 Weight, without engine (kg), if applicable    
B.2 Primemover    
B.2.1 Electric motor    
B.2.1.1 Brand    
B.2.1.2 Type    
B.2.1.3 Make or manufacturer    
B.2.1.4 Serial number    
B.2.1.5 Rated power (kW)    
B.2.1.6 Rated speed (rpm)    
B.2.1.7 Phase    
B.2.1.8 Voltage (V)    
B.2.1.9 Current (A)    
B.2.1.10 Frequency (Hz)    
B.2.2 Engine    
B.2.2.1 Brand    
B.2.2.2 Model    
B.2.2.3 Make or manufacturer    
B.2.2.4 Type    
B.2.2.5 Serial number    
B.2.2.6 Rated power (kW)    
B.2.2.7 Rated speed (rpm)    
B.2.2.8 Displacement (cm3)    
B.2.2.9 Cooling system    
B.2.2.10 Starting system    
B.3 Intake Hopper/Loading Pit    
B.3.1 Holding capacity (kg)    
B.3.2 Materials of construction    
B.3.3 Features    
B.4 Pre -cleaner    
B.4.1 Size (L x D), mm    
B.4.2 Materials of construction     
©RSB 2020 - All rights reserved                  8 
 B.5 Degerminator    
B.5.1 Type    
B.5.2 Size (L x D), mm    
B.5.3 Materials of construction    
B.6 Elevator(s)    
B.6.1 Type    
B.6.2 No. of units    
B.6.3 Size of buckets    
B.7 Steel Roller    
B.7.1 Size (L x D), mm    
B.7.2 No. of units    
B.7.3 No. of serration/inch    
B.7.4 Materials of construction    
B.8 Sifter    
B.8.1 Size (L x W), mm    
B.8.2 No. of screens    
B.8.3 Size of perforations, mm    
B.8.4 Length of stroke, mm    
B.8.5 Materials of construction    
B.9 Safety devices    
B.10 Special features    
 
 
 
 
 
 DRS  269-5:2020  
9                ©RSB2020 - All rights reserved  
 Annex  C 
(normative)  
 
Sampling and measurements for test material  
C.1 Sampling from different outlets  
C.1.1  During each test trial, three samples each shall be collected from the outlets of the different components 
of the maize mill to be analyzed in the laboratory.   
C.1.2  The minimum amount of sample to be taken shall be twice as much as what is needed for a particular 
analysis.   
C.1.3  The excess sample shall be used for reference purposes or for an eventual second check in case of 
review.  
C.2 Handling of samples  
C.2.1  All samples to be taken to the laboratory shall be placed in appropriate containers and properly labelled.   
C.2.2  If the sample is to be used for determining moisture content, it must be kept in dry and airtight 
containers.  
C.2 Other measurements required d uring the test run  
C.3.1 Data shall be taken for the following:   
a) speed of rotating components; and  
b) noise level at operator’s and bagger’s location.   
C.3.2  For each data to be taken, there shall be a minimum of five observations and shall be taken withou t and 
with load.   
C.3.3  Before taking of data, it should be ensured that the feed rate, speed and other functional characteristics 
have stabilized.   
C.3.4 The time of recording shall be properly spaced during the whole duration of the test trial.  
C.3 Measur ement of fuel consumption  
C.4.1 For maize mill using engine as prime mover  
C.4.1.1  To get the amount of fuel consumed, the tank shall be filled to full capacity before the test.   
©RSB 2020 - All rights reserved                  10 
 C.4.1.2  After the test, fill the tank with measured fuel to the same level be fore the test.   
C.4.1.3  When filling up the tank, careful attention shall be paid to keep the tank horizontal and not to leave 
empty space in the tank.  
12.1.1  C.4.2 Using electric motors as prime mover  
C.4.2.1  Use a power meter to measure the voltage, current and the total electric power consumption of the 
maize mill.   
C.4.2.2  There shall be three sets of data with a minimum of five observations per set taken with load and 
one set of data taken without load.   
C.4.2.3  Data shall be taken simultaneous with the collection of samples for laboratory analysis.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 DRS  269-5:2020  
11                ©RSB2020 - All rights reserved  
 Annex  D 
(normative)  
 
Performance test data sheet  
Test trial No.: _____________________   Date: _____________________   
Test Engineers: ____________________  Location: ________________________  
Assistants: _______________________   Test Specimen: _________________  
Tested requested by: _______________   Manufacturer: ____________________  
Table D 1 — Data sheet  
Items  Trial   
1  2  3  Average  
D.1 Conditions of Test Sample      
D.1.1 Variety      
D.1.2 Source      
D.1.3 Moisture content (%)      
D.2 Weight of input (kg)      
D.3 Weight of main products (kg)      
D.3.1 Grit #10      
D.3.2 Grit #12      
D.3.3 Grit #14      
D.3.4 Grit #16      
D.3.5 Grit #18      
D.4 Weight of by -products (kg)      
D.4.1 Grit #20      
D.4.2 Grit #24      
D.4.3 Floured maize (“tiktik”)      
D.4.4 Germs (“sungo”)      
D.4.5 Bran (“tahop”)      
D.5 Output time (h)      
D.6 Output capacity (t/h)       
©RSB 2020 - All rights reserved                  12 
 D.7 Milling time (h)      
D.8 Milling capacity (t/h)      
D.9 Total milling recovery      
D.9.1 Main product recovery (%)      
D.9.2 By -product recovery (%)      
D.10 Speed of components (rpm)      
D.10.1 Prime mover      
D.10.1.1Without load      
D.10.1.2With load      
D.10.2 Degerminator shaft      
D.10.2.1Without load      
D.10.2.2With load      
D.10.3 Aspirator shaft      
D.10.3.1Without load      
D.10.3.2With load      
D.10.4 Roller #1 shaft      
D.10.4.1 Without load      
D.10.4.2 With load      
D.10.5 Roller #2 shaft      
D.10.5.1 Without load      
D.10.5.2 With load      
D.10.6 Oscillating screen shaft      
D.10.6.1 Without load      
D.10.6.2 With load      
D.11 Noise level [db(A)]      
D.11.1 Operator      
D.11.1.1 Without load      
D.11.1.2 With load      
D.11.2 Bagger      
D.11.2.1 Without load      
D.11.2.2 With load      
D.12 Power consumption      
D.12.1 Power (kW)      DRS  269-5:2020  
13                ©RSB2020 - All rights reserved  
 D.12.1.1 Without load      
D.12.1.2 With load      
D.12.2 Current (A)      
D.12.2.1 Without load      
D.12.2.2 With load      
D.12.3 Voltage (V)      
D.12.3.1 Without load      
D.12.3.2 With load      
D.13 Fuel consumed (L)      
D.14 Fuel consumption (L/h)      
 D.15  Observations:  
D.15.1 Ease of loading  
___________________________________________________________________________ 
___________________________________________________________________________  
D.15.2 Ease of cleaning parts  
_________________________________ __________________________________________ 
___________________________________________________________________________  
D.15.3 Ease of adjustments  
___________________________________________________________________________ 
___________________________________________________________________________  
D.15.4 Ease of collecting output  
_____________________________________________________________________ ______ 
___________________________________________________________________________  
D.15.5 Safety   
©RSB 2020 - All rights reserved                  14 
 ___________________________________________________________________________ 
___________________________________________________________________________  
D.15 .6 Labour requirements  
___________________________________________________________________________  
___________________________________________________________________________  
D.15.7 Failure or abnormalities that may be observed on the maize mill or its component parts during 
and after the milling operation. 
___________________________________________________________________________ 
___________________________________________________________________________  
D.15.8 Others  
    ____________________________ _______________________________________________  
    ___________________________________________________________________________  
 
 
 
 
 
 
 DRS  269-5:2020  
15                ©RSB2020 - All rights reserved  
 Annex  E 
(normative)  
 
Laboratory analysis  
E.1 Purity determination  
E.1.1  Take three 500 g samples from the “representative samples” of the input.   
E.1.2  Clean the maize kernels to remove the impurities, the clean maize kernel shall be weighed and 
recorded.  
E.2 Moisture content  
E.2.1  Shall be taken using a calibrated meter or by o ven method.   
E.2.2  Five samples shall be taken for moisture content determination.   
E.2.4  The mean value determined from the 100 g samples shall be taken as the moisture content of the 
maize kernels.  
E.3 Analysis of output from degerminator to determine the  degerminator 
efficiency  
E.3.1  Three 100 g samples shall be taken from the output of the degerminator.   
E.3.2  These samples shall be analyzed to determine the percent degerminated, undegerminated and 
impurities.  
E.4 Analysis of main products  
E.4.1  This proce dure shall be used to determine the percentage of the maize grits for that particular maize 
grits size and at the same time, to determine the percentage of maize grits of other sizes. E.4.2  In each test 
trial, take three 100 g samples from each main produc t outlet.   
E.4.3  Using laboratory sieve shaker with a sieve of the same size with the main product to be analyzed, get 
the weight of the sample that passed through the sieve but did not pass through the next sieve size.   
E.5 Analysis of by -products  
E.5.1  In each test trial, take three 100 g samples from each of the outlet of floured maize, germs and bran.   
E.5.2  Separate any impurities and take the final weight of the sample.   
©RSB 2020 - All rights reserved                  16 
 E.6 Analysis of output from roller mill to compare laboratory result with 
machine’s o utput  
E.6.1  In each test trial, take three100 g samples from the roller mill output.   
E.6.2  Using laboratory sieve shaker with sieves of the same sizes (for the main product) with the maize mill, 
get the weight of the samples that remained on each sieve a nd determine the percentages of maize grits 
(main products).   
E.6.3  Compare the result with the output (main product) of the maize mill.  
 DRS  269-5:2020  
17                ©RSB2020 - All rights reserved  
 Annex  F 
(normative)  
 
Laboratory test data sheet  
Machine Tested: _________________________________________________________ 
Analyzed by: ____________________________________________________________  
12.2 F.1 Moisture content determination  
 F.1.1  Using calibrated moisture meter  
 Moisture content (%) _______  _ _______   ________   _________  Average________  
 F.1.2  Oven method (100 g sample)  
 Final weight (g)   ________  ________   ________    Average________  
 Moisture content (%)  ________   ________   ________    Average________  
12.3 F.2 Purity determination (5 00 g sample)  
 Final weight (g)   ________  ________   ________    Average________  
 Purity (%)    ________   ________  ________    Average________  
Table F.1 — Analysis of output from degerminator  
Items  Trial 1  Trial 2  Trial 3  Average  
A Initial weight of sample (g)      
B Weight of degerminated maize kernels (g)      
C Weight of undegerminated maize kernels (g)      
D Weight of impurities (g)      
 
Table F.2 — Analysis of output from roller mill (using Laboratory Sieve Shaker)  
 Items  Trial 1  Trial 2  Trial 3  Average   
©RSB 2020 - All rights reserved                  18 
 c)  Grit # 10  
Wt. of size #10 grits  
Percentage weight      
d)  Grit # 12  
Wt. of size # 12 grits  
Percentage weight      
e)  Grit # 14  
Wt. of size #14 grits  
Percentage weight      
f)  Grit # 16  
Wt. of size # 16 grits  
Percentage weight      
g)  Grit # 18  
Wt. of size # 18 grits  
Percentage weight      
Table F.3 — Analysis of main products (using Laboratory Sieve Shaker)  
 Items  Trial 1  Trial 2  Trial 3  Average  
h)  Grit # 10  
Wt. of size #10 grits  
Wt. of other size of grits      
i)  Grit # 12  
Wt. of size # 12 grits  
Wt. of other size of grits      
j)  Grit # 14      
 Wt. of size #14 grits  
Wt. of other size of grits      DRS  269-5:2020  
19                ©RSB2020 - All rights reserved  
 k)  Grit # 16  
Wt. of size # 16 grits  
Wt. of other size of grits      
l)  Grit # 18  
Wt. of size # 18 grits  
Wt. of other size of grits      
 
Table F.4 — Analysis of by -products  
Items  Trial 1  Trial 2  Trial 3  Average  
F.6.1 Floured maize (100 g)  
Final weight of sample (g)  
Weight of impurities (g)      
F.6.2 Germs (100 g)  
Final weight of sample (g)  
Weight of impurities (g)      
F.6.3 Bran (100 g)  
Final weight of sample (g)  
Weight of impurities (g)      
 
 
 
  
©RSB 2020 - All rights reserved                  20 
 Annex  G 
(normative)  
 
Formula used during calculations and testing  
G.1 Input capacity,  
 
G.2 Output capacity,  
 
G.3 Milling capacity,  
 
G.4 Main product recovery,  
 
G.5 By-product recovery,  
 
G.6 Losses,  
 
G.7 Fuel/Electrical consumption  
 G.7.1  Fuel consumption,  
DRS  269-5:2020  
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 G.7.2  Electrical energy consumption,  
 
 
DRS  269-5:2020  
 
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