UGANDA STANDARD  
  US 775-1
First Edition
2008-09-08
 
 
Reference numbe r
US 775-1: 2008
 © UNBS 2008 
  
Retro – reflective registration plates for motor vehicles — 
Specification — Part 1: Blanks (metal) 
 US 775-1: 2008 
 © UNBS 2008 – All rights reserved
ii Compliance with this standard does not, of itself confer immunity from legal obligations 
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2008  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, in cluding photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala  
Uganda 
Tel: 256 414 505 995 
Fax: 256 414 286 123 
E-mail: unbs@infocom.co.ug
Web: www.unbs.go.ug  US 775-1:2008 
iii © UNBS 2008 – All rights reserved  
 Contents Page 
Foreword .............................................................................................................................................................v  
1 Scope ......................................................................................................................................................1  
2 Normative references ............................................................................................................................1  
3 Terms and definitions ...........................................................................................................................1  
4 Requirements .........................................................................................................................................2  
4.1 Type of blank .........................................................................................................................................2  
4.2 Materials .................................................................................................................................................2  
4.2.1 Metal ........................................................................................................................................................2  
4.2.2 Retro-reflective material .......................................................................................................................2  
4.3 Embossed border colour and luminance factor ................................................................................3  
4.3.1 Colour of embossed border .................................................................................................................3  
4.3.2 Luminance factor ...................................................................................................................................4  
4.4 Shape and dimensions .........................................................................................................................4  
4.5 Preparation of the plate ........................................................................................................................5  
4.5.1 Cleanliness .............................................................................................................................................5  
4.5.2 Coating of aluminium ............................................................................................................................5  
4.6 Application of retro-reflective material ...............................................................................................5  
4.7 Embossed border ..................................................................................................................................5  
4.8 Workmanship .........................................................................................................................................5  
4.9 Performance tests .................................................................................................................................6  
4.9.1 Resistance to weathering .....................................................................................................................6  
4.9.2 Resistance to impact .............................................................................................................................6  
4.9.3 Resistance to scratching ......................................................................................................................6  
4.9.4 Resistance to salt fog ...........................................................................................................................6  
4.9.5 Resistance to bending ..........................................................................................................................6  
5 Inspection and methods of test ...........................................................................................................6  
5.1 General ...................................................................................................................................................6  
5.2 Inspection ...............................................................................................................................................6  
5.3 Test specimens ......................................................................................................................................7  
5.4 Resistance to weathering .....................................................................................................................7  
5.4.1 Apparatus ...............................................................................................................................................7  
5.4.2 Temperature measurement ..................................................................................................................8  
5.4.3 Temperature control ..............................................................................................................................8  
5.4.4 Procedure ...............................................................................................................................................8  
5.5 Resistance to impact .............................................................................................................................8  
5.5.1 Apparatus ...............................................................................................................................................8  
5.5.2 Procedure ...............................................................................................................................................9  
5.6 Resistance to scratching ......................................................................................................................9  
5.6.1 Apparatus ...............................................................................................................................................9  
5.6.2 Procedure ...............................................................................................................................................9  
5.7 Resistance to salt fog ...........................................................................................................................9  
5.7.1 Apparatus ...............................................................................................................................................9  
5.7.2 Salt solution ............................................................................................................................... ..........10  
5.7.3 Conditions of test ............................................................................................................................... .10 
5.7.4 Procedure ............................................................................................................................... ..............10  
5.8 Bending test ............................................................................................................................... ..........11  
5.9 Colour and luminance factor test ......................................................................................................11  
5.10 Photometric test ............................................................................................................................... ...11 
6 Packing and marking ..........................................................................................................................11  US 775-1: 2008 
 © UNBS 2008 – All rights reserved
iv 6.1 Packing ............................................................................................................................... ................. 11  
6.2 Marking ............................................................................................................................... ................. 11  
 US 775-1:2008 
v © UNBS 2008 – All rights reserved  
  
Foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry  of Tourism, Trade and 
Industry established under Cap 327, of the Laws of Uganda.  UNBS is mandated to co-ordinate the 
elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex A limentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agr eements of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a gi ven field or area and consists of representatives of 
consumers, traders, academician s, manufacturers, governme nt and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committ ee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
Committee membership 
The following organizations were represented on the Technical Committee for Transport and Communication standards, UNBS/TC 8, in the development of this standard: 
• Arnold Brooklyn and Company Ltd 
• GM Tumpeco Ltd 
• Makerere University 
• Ministry of Works and Transport 
• Uganda Revenue Authority 
• Uganda Manufacturers Association (UMA) 
• Uganda National Bureau of Standards 
 UGANDA STANDARD US 775-1: 2008
 
1 
 Retro – reflective registration plates for motor vehicles —
Specification — Part 1: Blanks (metal) 
1 Scope 
1.1 This part of US 775 specifies require ments for the type of blank intende d for use in the production of the 
embossed registration plates that are covered by US 775-2. 
1.2 Except under the certification mark scheme, a special agreement between the manufacturer and the 
purchaser is required for assessment of compliance wi th the requirements of US 775-1 of those blanks on 
which the retro-reflective material is applied during the process of embossing the registration number. 
2 Normative references 
The following referenced documents are indispensable for the application 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. 
CIE Publication 15 (E.1.3.1), Colorimetry 
CIE Publication 54, Retro-reflection: Definitions and measurement 
ISO 7591 Road vehicles — Retro-reflective registration plates  for motor vehicles and trailers — Specification 
Traffic and Road Safety Act, 1998 
US 775-2, Retro-reflective registration plates  for motor vehicles — Specification — Part 2:  Metallic registration 
number plates  
US ISO 9001, Quality management systems — Requirements  
3 Terms and definitions 
For the purposes of this standard, the following terms and definitions shall apply. 
3.1  
blank 
flat metal plate that has, on one side, an embossed border and at least the area within this border covered 
with retro-reflective material, the material being suppli ed as a loose sheet if it is intended to be subsequently 
applied as part of the embossing proc ess of the registration number 
3.2  
category L motor vehicle 
motor vehicle that has fewer than four wheels US 775-1: 2008 
 © UNBS 2008 – All rights reserved
2 3.3  
embossing 
process by which a raised border is embossed onto a plat e (to form a blank) or by which characters are so 
embossed onto a blank that they stand out in relief on the retro-reflective surface of a registration plate 
3.4  
illuminants A and D65 
illuminants A and D65 as defined by the International Commission on illumination (CIE) in Publication 15 
(E.1.3.1) 
3.5  
luminance factor (at a point on the surface of a non-self-radi ating body, in a given direction, and under 
specific conditions of illumination) 
ratio of the luminance of the material to that of  a perfect reflecting diffuser identically illuminated 
3.6  
registration mark/registration number  
combination of letters and numerals as prescrib ed by the Traffic and Road Safety Act, 1998  
3.7  
registration plate; plate 
plate that displays the registration mark of a motor vehicle or trailer  (see Figures 3 - 7 of US 775-2) 
3.8 
retro-reflection 
reflection in which light is reflected in directions close to the direction of incidence, irrespective of the angle of 
incidence at the reflecting surface 
3.9 
retro-reflective sheeting 
multi-layer film with small retro-reflective elements very near the exposed surface 
4 Requirements 
4.1 Type of blank 
A blank shall be of a type in which the front face is co mpletely covered with retro- reflective material and is 
intended for use in an embossing proc ess in which the raised surfaces of the characters and the embossed 
border are coated. 
4.2 Materials 
4.2.1 Metal 
The metal base of a blank shall be of aluminium sheet material of thickness at least 1.0 mm ± 0.1 mm and 
shall be suitable for the embossing process. 
4.2.2 Retro-reflective material 
4.2.2.1 Colour and luminance factor 
4.2.2.1.1 When determined in accordance with 5.8, the col our of the retro-reflective material shall be 
yellow, blue, red or white and the chromaticity co-ordinat es shall be within the area on a chromaticity diagram 
defined by the points of the appropri ate values given in Table 1. US 775-1:2008 
3 © UNBS 2008 – All rights reserved  
 4.2.2.1.2 When determined in accordance with 5.8, the lumina nce factor of the material shall be at least the 
appropriate value given in Table 1. 
Table 1 — Chromaticity co-ordinates and luminance factors 
Value of co-ordinate Colour Co-ordinate 
1 2 3 4 Luminance 
factor min. 
Yellow X 
y 0.545 
0.454 0.487 
0.423 0.427 
0.483 0.465 
0.534  
0.27 
White X 
y 0.355 
0.355 0.305 
0.305 0.285 
0.325 0.335 
0.375  
0.35 
NOTE For legislation regarding the co lour of registration plates, see Road Traffic Safety Act (Act of 1998) 
 
4.2.2.2 Coefficients of retro-reflection  
When the coefficients of retro-reflection of the material  are determined in accordance wi th 5.9, they shall be at 
least the relevant values given in Table 2. 
Table 2 – Coefficients of retro-reflection 
Coefficient of retro-reflection 
when measured with standard 
illuminant, 
cd/(lx.m2) min. Observation angle 
degrees Entrance angle, 
degrees 
1 2 
0.33* 
2 5*
30 35 
1.5 50 
2.5 
* The coefficient of retro-reflection at an angle of observation and an entrance angle of 
0.33° and 5° respectively, shall not exceed 100 cd/(lx.m ) for yellow material and 160 cd/(lx.m ) 
for white material.2 2
 
4.2.2.3 Flexibility 
After wrapping a piece of retro-reflective material of  size 200 mm x 100 mm, complete with protective lining for 
surface outwards, lengthways around a mandrel of diameter 20 mm and length at least 250 mm (that is, the 
retro-reflective material has been wrapped with its longer ax is parallel to that of the mandrel), there shall be no 
evidence of cracking of the retro-reflective material. 
4.2.2.4 Validation mark 
The blank material shall bear a serial number and a valid ation mark that identifies the manufacturer of the 
material. 
4.3 Embossed border colour and luminance factor 
4.3.1 Colour of embossed border 
The colour of the embossed border shall be black, blue, red, green or white. US 775-1: 2008 
 © UNBS 2008 – All rights reserved
4 4.3.2 Luminance factor 
When the luminance factor of the colours blue, red, green and white  is determined in accordance with 5.8, it 
shall be less than 0.12. 
4.4 Shape and dimensions 
Blanks shall be rectangular and shall be of one of t he following sizes as shown in Tables 3 and 4. 
Table 3 — Dimensions for motor vehicle plates 
Vehicle Size 
Public vehicle plates: 
 Front 
 Back  
(520 mm x 110 mm) ± 3 mm 
(230 mm x 205 mm) ± 3 mm 
Diplomat/CD vehicle plates: 
 Front 
 Back (520 mm x 110 mm) ± 3 mm 
(340 mm x 205 mm) ± 3 mm 
Government vehicle plates: 
 Front 
 Back (520 mm x 110 mm) ± 3 mm 
(340 mm x 205 mm) ± 3 mm 
Duty free vehicle plate: 
 Front 
 Back (520 mm x 110 mm) ± 3 mm 
(340 mm x 205 mm) ± 3 mm 
Personalized vehicle plate: 
 Front 
 Back (520 mm x 110 mm) ± 3 mm 
(340 mm x 205 mm) ± 3 mm 
 
Table 4 — Dimensions for category “L” motor vehicles 
Vehicle Size 
Public motor cycles plates: 
 Front 
 Back (255 mm x 135 mm) ± 3 mm 
(255 mm x 135 mm) ± 3 mm 
Government motor cycle plates: 
 Front 
 Back (255 mm x 135 mm) ± 3 mm 
(255 mm x 135 mm) ± 3 mm 
Duty free vehicle plates: 
 Front 
 Back (240 mm x 135 mm) ± 3 mm 
(240 mm x 135 mm) ± 3 mm US 775-1:2008 
5 © UNBS 2008 – All rights reserved  
 4.5 Preparation of the plate 
4.5.1 Cleanliness 
The surface of the metal base to which the retro-reflec tive material is applied shall be dry and free from 
grease, oil, corrosion and any form of  contamination before the retro-reflective material is applied (see 4.6) 
and, when relevant, before it is coated (see 4.5.2). 
4.5.2 Coating of aluminium 
4.5.2.1 Aluminium blanks 
The surfaces of each blank that have an aluminium bas e and that are coated [before the application of the 
retro-reflective material see 4.6)] shall be coated with 
a) a powder coating of dry film thickness at least 35 μm, or 
b) a suitable surface-co nversion coating, followed by a coat (of a dry film thickness at least 20 μm) of a 
baking enamel. 
4.6 Application of retro-reflective material  
Blanks, other than those on which the retro-reflective material is intended to be applied during the process of 
embossing the registration number, shall have the material  applied to the front surface. The retro-reflective 
material shall be of such a size that, the retro-reflective  material covers the entire su rface of the blank so that 
at no part is the width of the retro-reflective material less than the width of the blank by more than 2 mm,  and 
at no part is the distance between the edges of the retr o-reflective material and the adjacent edges of the 
blank more than 1.3 mm. 
4.7 Embossed border 
The embossed border of a blank shall be of curved or fl at cross-section, generally as given in Figure 1. The 
embossing shall extend around the periphery of the bl ank and shall have an overall width of 5 mm ± 1 mm 
and a height above the surface of the blank of, not less than 1 mm and not more than 2 mm.  
 
 
Figure 1 — Typical embossed border 
4.8 Workmanship 
Blanks shall be free from creases, crevices and sharp or jagged edges, and retro-reflective and coated 
surfaces shall be free from creases, cracks,  chips, blisters, discoloration and spots. US 775-1: 2008 
 © UNBS 2008 – All rights reserved
6 4.9 Performance tests 
4.9.1 Resistance to weathering 
When blanks are tested in accordance with 5.4, 
a) the chromaticity co-ordinates shall remain within  the area on the appropriate chromaticity diagram as 
 defined in 4.2.2.1; 
b) the coefficient of retro-reflection at an angle of observation and an entrance angle of 0.33 ° and 5 ° 
respectively, shall be at least 80 % of the minimum values given in Table 2; 
c) the retro-reflective material s hall show no sign of cracking, blistering, or loss of adhesion; and 
d) when relevant, the painted or powder-coated surf ace shall show no sign of chalking or checking. 
4.9.2 Resistance to impact 
When blanks are tested in accordance with 5.5, the retr o-reflective material and (when relevant) the painted or 
powder-coated surface shall show no sign of cracking or loss of adhesion. 
4.9.3 Resistance to scratching 
When blanks are tested in accordan ce with 5.6, the scratch produced 
a) on the retro-reflective surface shall no t have penetrated the material surface, and 
b) on the painted or powder-coated surface (when rele vant), shall be free from jagged edges and shall
 not  have penetrated through to the substrate. 
4.9.4 Resistance to salt fog 
When blanks are tested in accordance with 5.6, no surf ace shall show any sign of  delamination, edge lifting or 
loss of adhesion. In the case of a retro-reflective surface, there shall be no sign of corrosion or blistering. In 
the case of a painted or powder-coat ed surface, any blister or creep (or both) or corrosion shall not extend 
further than 2 mm on each side of the scribe mark. 
4.9.5 Resistance to bending 
When blanks are tested in accordance with 5.8, t here shall, after each bending operation, be no sign of 
cracking of the metal, or of cracking or loss of adhesion of the retro-reflective material or (when relevant) of 
the paint or powder coating. 
5 Inspection and methods of test 
5.1 General 
In the case of blanks where the retro-reflective material is intended to be applied as part of the embossing 
process of the registration number, inspection and tests shall be carried out on test specimens on which the 
retro-reflective material has been permanently applied using the registration number embossing process but 
without a number having been embossed. 
5.2 Inspection 
Visually examine and measure each blank in the sample  for compliance with all the appropriate requirements 
of this standard for which tests to assess comp liance are not given in 5.4 to 5.8 (inclusive). 
 US 775-1:2008 
7 © UNBS 2008 – All rights reserved  
 5.3 Test specimens 
From sample blanks, cut the following test specimens: 
a) resistance to weathering: one test specimen of width at least 70 mm and of length at least 150 mm, 
and that has not more than one cut edge; 
b) resistance to impact : one test specimen of any convenient size; the test may be carried out on an 
end of the specimen cut in terms of (e) below before it is subjected to bending; 
c) resistance to scratching : one test specimen of width at least 55 mm and of length at least 100 mm; 
d) resistance to salt fog : one test specimen in the case of a blank without any paint or powder coating 
on  the rear surface, and two test specimens in other cases, each of width at least 100 mm and of 
length at  least 100 mm and that have not more than two cut edges; 
e) bending test : one test specimen of width between 100 mm and 120 mm and of length at least 250 
mm, and that has embossed on it one character of a registration mark that complies with the  appropriate requirements of US 775-2.   
5.4 Resistance to weathering 
5.4.1 Apparatus 
A weathering unit , that has the following features: 
a) Test chamber  constructed of corrosion-resistant material s enclosing eight fluorescent UV lamps, a 
heated water pan, test specimen racks that constitu te the side walls of the chamber, and provisions 
for controlling and recording operating times and temperatures 
b) Lamps,  of type UVB 313 fluorescent UV lamps or equiva lent, the spectral energy distribution curve 
having a maximum at a wavelength of 313 nm with less than 1 % of the peak intensity at 280 nm. 
The lamps are of length 1 220 mm and of nominal rating 40 W when operated from a ballast that 
provides a controlled current of 430 mA at 102 V. 
c) Lamp and test specimen arrangement  with the lamps mounted in two banks of four lamps each to 
provide a uniform distribution of irradiance. The lamps in each bank are mounted parallel to each 
other at 70 mm centres. The test specimens are mounted in two stati onary racks each of height 300 
mm and of  width 1 154 mm, the test surface being in each case parallel to the plane of one bank 
of lamps and at a distance of 50 mm fr om the nearest surface of the lamps. 
d) Condensation mechanism  where water vapour is generated by  the heating of a water pan that 
extends under the entire specimen area and contains water of depth 25 mm. The back surface of each specimen is exposed to the cooling effect of the ambient room air. The resulting heat transfer 
causes water vapour, saturated with air, to conde nse on the test surface. The specimens are so 
arranged that condensate runs off the test surfac e by gravity and is replaced by fresh condensate in 
a continuous process. Vents along the bottom of the test chamber are provided to admit ambient air 
and so prevent oxygen depletion of the condensate. 
e) Water supply  with an automatic control to regulate the level in the water pan. Distilled, de-ionized, or 
potable tap water may be used. 
f) Cycle timer that is continuously operating provided to program the selected cy cle of UV radiation 
periods and condensation periods. An hour meter is provided to record the total time of operation and 
total time of UV exposure. US 775-1: 2008 
 © UNBS 2008 – All rights reserved
8 5.4.2 Temperature measurement 
5.4.2.1  The temperature is measured by means of a thermometer, the bulb of which is inserted in a black 
aluminium panel of size 75 mm x 100 mm x 2.5 mm. The t hermometer is accurate to 1 °C through a range of 
30 °C to 80 °C. The indicator of the thermometer is located outside the test chamber. 
5.4.2.2  The black aluminium panel and thermometer bulb ar e so positioned in the centre of the exposure 
rack that they are subjected to the same conditions as the specimens. 
5.4.3 Temperature control 
5.4.3.1 During UV exposure, the selected equilibrium temp erature is maintained within 3 °C by the supply 
of heated air to the test chamber.  
5.4.3.2 During condensation exposure, the selected equilibri um temperature is maintained within 3 °C by 
the heating of the water in the pan. 
5.4.3.3 The UV and condensation temperature controls are independent of each other. 
5.4.3.4 Doors are located on the room air side of the sp ecimen rack, to act as insulation during the UV 
exposure and to minimize draughts. The doors do not interfere with the room air cooling of the specimen 
during the condensation exposure. 
5.4.4 Procedure 
5.4.4.1  Seal the cut edge of each specimen [see 5.3 (a)]. 
5.4.4.2  Mount the test specimens in the specimen racks, with the test surfaces facing the lamps. 
5.4.4.3  Select the following cycle conditions: 
a) 4 h UV exposure at 60 °C; and then 
b) 4 h condensation exposure at 50 °C. 
5.4.4.4 Except for servicing the apparatus and inspecti ng the specimens, repeat the cycle continuously 
for 240 h. 
5.4.4.5 At regular intervals during the specified ex posure period, examine the specimens under 10x 
magnification. 
5.4.4.6 Check for compliance with 4.9.1. 
5.5 Resistance to impact 
5.5.1 Apparatus 
5.5.1.1 Striker,  a cylindrical piece of steel of length and diameter approximately 230 mm and 25 mm 
respectively, that has a hardened steel ball of diam eter 12.7 mm ± 0.1 mm mounted at its bottom end and a 
total mass of 900 g ± 10 g 
5.5.1.2 Drop tube,  a slotted or split vertical tube graduated  in millimetres, of approximate length 500 mm 
and of diameter large enough to enable the striker to drop freely through it 
5.5.1.3 Base plate,  a horizontal steel plate that has a hole of  diameter 16 mm, the plate being so placed 
that the hole is concentric with the opening of the tube US 775-1:2008 
9 © UNBS 2008 – All rights reserved  
 5.5.2 Procedure 
5.5.2.1 So place the specimen [see 5.3 (b)] over the hole in the base plate that the striker will fall onto a 
part of a retro-reflective surface of the specimen. 
5.5.2.2 Raise the striker to the appropriate height and allow it to fall with an energy of 1.15 J for 
aluminium blanks. 
5.5.2.3 When relevant, repeat 5.5.2.1 and 5.5.2.2, but with the point of impact being on a part of a 
painted or powder-coated surface. 
5.5.2.4 Examine the dented part(s) of the specimen under 10x magnification for compliance with 4.9.2. 
5.6 Resistance to scratching 
5.6.1 Apparatus 
5.6.1.1 Needle and arm : a needle with a hardened steel hemisphe rical point of diameter 1 mm, fixed 
vertically, point downwards, to the end of a counterpois ed horizontal arm. The horiz ontal arm provides for the 
loading of masspieces above the needle direct, and it may be set in equilibrium on its fulcrum by adjustment of 
the countermass before masspiec es are loaded above the needle. 
5.6.1.2 Masspieces , a set of forty 50 g masspieces 
5.6.1.3 Base with sliding specimen holder , that moves freely and automatically on its base under the 
loaded needle (which is perpendicular to the specimen holder) 
5.6.1.4 Electric current supply and ammeter . The needle and specimen holder are so connected in 
series with an ammeter and an electric current supply  that, when the painted or powder-coated surface of a 
specimen is penetrated, the needle makes electrical contac t with the underlying metal, and this penetration is 
indicated by a flow of current through the ammeter. 
5.6.2 Procedure 
5.6.2.1 In the case of a retro-reflective  surface, set the horizontal arm in equilibrium, with the electric 
current supply and ammeter not in use. Clamp the specimen [see 5.3 (c)] to the specimen holder, with the 
material to be tested facing upwards. Load the needle with masspieces of total mass 2 000 g and lower the 
needle carefully onto the material surface while starting to slide the holder. Alternatively, so put the end of the 
needle on a razor blade on the material surface that the needle can slide off the sharp edge of the blade onto 
the surface. Slide the holder at a uniform speed of  approximately 30 mm/s for a distance of about 90 mm. 
5.6.2.2 Examine the edges of the groove under 10x magnification. 
5.6.2.3 Check for compliance with the re levant requirements of 4.9.3. 
5.6.2.4 Repeat 5.6.2.1 to 5.6.2.3 on two other  parts of the material surface. 
5.6.2.5 In the case of a painted or powder-coated surface, ca rry out the test as given in 5.6.2.1 to 5.6.2.4, 
but with the electric current supply and ammeter in use. 
5.7 Resistance to salt fog 
5.7.1 Apparatus 
A fog cabinet , that has the following features: US 775-1: 2008 
 © UNBS 2008 – All rights reserved
10 a) Exposure chamber , made from, or coated with, a corrosion-re sistant material and, so constructed that 
the salt fog circulates freely and equally about all specim ens, and that has baffles to prevent the salt fog 
from striking the specimens direct 
b) Racks for supporting the specimens, removable and made from, or coated with, a corrosion-resistant 
material and so constructed that the specimens ar e held without touching one another or any other metal 
and that salt solution will not drip from one specimen onto another. 
c) Salt solution reservoir, of adequate size to produce the require d quantity of salt fog and made from, or 
coated with, corrosion-resistant material. It is so co nstructed that there is no recirculation of the salt 
solution 
d) Atomizing nozzles, plastics nozzles so designed that they will produce a finely divided salt solution fog 
e) Air supply : a compressed air supply for the atomizing nozzles, filtered to remove all impurities. Means 
are provided to humidify and heat the compressed air as ne cessary. The air pressure is constant to within 
700 Pa and sufficient to produce a finely divided salt solution fog. 
f)  Heating of chamber and temperature control : the exposure chamber is heated and its temperature is 
controlled by means of a thermostat. 
 NOTE – An immersion heater should not be used. 
5.7.2 Salt solution 
The salt solution is made up as follows: 
a) Salt: sodium chloride containing sodium iodide not ex ceeding 1 g/kg of salt and total impurities not 
 exceeding 3 g/kg of salt, calculated on the dry basis 
b) Water  that contains total solids not exceeding 200 mg/kg of water 
c) The salt solution is prepared by dissolving 5 parts ± 0.5 parts (by mass) of salt in 95 parts (by mass) 
of water and filtering the solution. 
5.7.3 Conditions of test 
5.7.3.1 Temperature 
Maintain the temperature in the exposure zone at 33 °C to 36 °C. 
5.7.3.2 Salt fog 
Ensure that the degree of atomizati on of the salt solution is such that  suitable fog collectors placed at any 
point in the exposure zone will collect, over an average r unning period of at least 16 h, 65 mL to 375 mL of 
solution per hour per square metre of horizontal collecting area. Ensure that the solution so collected has a pH 
value of 6.5 to 7.2 when measured electrometrically. 
5.7.4 Procedure 
5.7.4.1 In the case of specimens [see 5.2(d)] that have a paint or powder coating, use a suitable cutting 
tool and carefully make (with the cutting edge of the cutting tool held at an angle of about 30° to the surface 
and the plane of the blade perpendicular to that surface) a scribe mark of length about 75 mm, by cutting through the coating to the base. 
5.7.4.2 Establish the test conditions in the exposure chamber. Mount the specimens on the supporting 
racks and insert the racks in the exposure chamber. US 775-1:2008 
11 © UNBS 2008 – All rights reserved  
 5.7.4.3 Close the exposure chamber and operate the cabinet continuously for 24 h.  
5.7.4.4 After the test period, remove the specimens and rinse them thoroughly with distilled water. 
Examine the following for compliance with the applicable requirements of 4.9.4: 
a) when relevant, the paint or powder coating, i mmediately after removal of the specimens from the
 exposure chamber; and 
b) the retro-reflective material, after a 24 h recovery period has elapsed. 
5.8 Bending test 
So place the unlaminated surface of the test specimen [see 5.2(e)] against a mandrel of diameter 50 mm ± 1 
mm that the line of maximum bending coincides with the ve rtical centre-line of the letter or numeral. Taking 
about 3 s, bend the specimen through an angle of 90° ± 2° over the mandrel, and then examine it for 
compliance with 4.9.5. Immediately following this proc edure, and taking about 3 s, so bend the specimen back 
through the same angle that it is in approximately it s original alignment and again examine it for compliance 
with 4.9.5.  
5.9 Colour and luminance factor test 
Determine the chromaticity co-ordinates and luminance factors of the relevant areas of the specimen by 
means of a spectrophotometer or other equally suitabl e colour measuring device in accordance with CIE 
Publications 15 (E.1.3.1) and 54, using Standard Illuminant D65 and 45/0 geometry. 
Check for compliance with 4.2.2.1. 
5.10 Photometric test 
Determine the coefficients of retro-reflection in acco rdance with CIE Publication 54, using the values of 
observation angle and entrance angle given in Table 2. On  each specimen, take the average of two readings 
at rotation angles (about the reference axis) that are 90° apart. Check for compliance with 4.2.2.2. 
6 Packing and marking 
6.1 Packing 
The blanks and, when relevant, the retro-reflective material  shall be so packed as to ensure that they are not 
damaged during normal handling, transportation and storage. 
6.2 Marking 
Each blank shall bear the manufacturer’s trade name or trade mark, serial number, Uganda flag and security hologram in legible and indelible marking, on the surface covered or not covered by the retro-reflective 
material. The Uganda flag, security hologram and seri al number shall be on the left hand side of plate covered 
by the retro-reflective material. The Uganda flag sha ll be on top, security hologram in the middle and serial 
number at the bottom in that order.  US 775-1: 2008 
 © UNBS 2008 – All rights reserved
12 Annex A 
(normative) 
 
Quality verification of metal blanks for retro-reflective registration plates 
When a purchaser requires ongoing verification of the qua lity of metal blanks for retro-reflective registration 
plates, it is suggested that, instead of concentrating so lely on evaluation of the final product, he also directs 
his attention to the manufacturer's quality system. In this connection it should be noted that US ISO 9001 
covers the provision of an integrated quality system. 
 
 US 775-1:2008 
13 © UNBS 2008 – All rights reserved  
 Certification marking 
Products that conform to Uganda standards may be  marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is gove rned by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licens ed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in co njunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and  testing in accordance with the 
certification mark scheme of the Uganda National  Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of  licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 US 775-1:2008 
 
ICS nn.nnn.nn 
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© UNBS 2008– All rights reserved