CONAMA Resolution 1/93

CONAMA RESOLUTION 1, February 11, 1993
Published in Official Gazette 31 on Feb. 15, 1993, Section 1, pages 2037-2040
· Changed by CONAMA Resolution 8/93 (changes art. 1 and §§ and table 1)
· Changed by CONAMA Resolution 17/95 (changes annex 1) in cases related to vehicles that are produced from a bus chassis or bus platform undercarriage, supplied by a third party
· Complemented by CONAMA Resolution 242/98 related to vehicles with special characteristics for use outside of roads (table 1)
· Changed by CONAMA Resolution 272/00 (changes art. 2 and §§ 2 and 3 of art. 7) and establishes new limits for vehicles produced from January 2001 (table 1)
Establishes maximum noise limit levels for vehicles while running but still or in acceleration, national or imported, with the exception of motorcycles, scooters, mopeds, tricycles and bicycles with auxiliary engines or similar vehicles.

The NATIONAL ENVIRONMENT COUNCIL – CONAMA, in the use of the power bestowed upon the Council by Laws 6.938 from Aug. 31, 1981, 8.028, from April 12, 1990, 8.490 from November 19, 1992, Decree 99.274 from June 6, 1990 and in light of its Internal Regulations, and

Considering that excessive noise if hazardous to physical and mental health and has a particular effect on hearing;

Considering the need to reduce Sound pollution within urban centers;

Considering that roadway motor vehicles are the main environmental noise sources;

Considering that the use of known adequate technologies allows for the control of sound pollution;

Considering the objectives of the National Program for Education and Control of Sound Pollution “SILÊNCIO”, decides:

Art. 1 To establish maximum noise limits for national and imported vehicles, except motorcycles, scooters, tricycles, mopeds and bicycles with auxiliary engines and similar vehicles, both while running but still and during acceleration.

§ 1 Nationally produced vehicles for national market purposes the noise limits will enter into effect for accelerating vehicles as defined by table 1 and according to the below schedule by brand :

a) cycle Otto motor vehicles except for those in the “c” and “d” categories;
a.1) a minimum of 20% of all produced vehicles from Jan. 1st 1994;
a.2) a minimum of 50% of all vehicles produced from Jan. 1st, 1995;
a.3) 100 % of all produced vehicles form Jan. 1st, 1997;

b) Diesel vehicles and vehicles possessing Otto Cycle engines of “c” and “d” categories:
b.1) A minimum of 405 of all produced vehicles from Jan. 1st 1995;
b.2) 100% of all vehicles produced from Jan.1st , 1997;

§ 1 The noise limits for nationally produced vehicles for national market purposes will enter into effect for accelerating vehicles according to the below schedule and brand, as defined by table 1 of this Resolution:

a) cycle Otto motor vehicles except for those in the “c” and “d” categories;
a.1) a minimum of 20% of all produced vehicles from March. 1st 1994;;
a.2) a minimum of 50% of all vehicles produced from Jan. 1st, 1995
a.3) 100 % of all produced vehicles form Jan. 1st, 1997;

b) all Diesel motor vehicles and auto motor vehicles possessing Otto cycle engines of “c” and “d” categories:
b.1) minimum of 40% for vehicles produced from Jan. 1st, 1996;
b.2) 100% of cycle OTTO engines produced from Jan. 1st, 1997;
b.3) 100% of all vehicles produced from Jan. 1st, 1998 .
(new text provided by Resolution 8/93)

Category Noise Level / Level dB(A)
Description Otto Diesel
Direct Injection Indirect Injection
A Passenger cars of up to nine places and mixed-use vehicle derived from a car 77 78 77
B Passenger vehicle with more than nine seats, cargo or traction vehicle mixed purpose vehicle not derived from a car PTB up to 2.000 kg 78 79 78
PTB above 2000 kg
and up to3.500 kg
79 80 79
C Passenger or mixed use vehicle with PTB greater than 3500 kg Maximum power below 150 kW
(204 CV)
80 80 80
Maximum power equal
or above 150 kW
(204 CV)
83 83 83
D Cargo vehicle or with a PTB traction above 3.500 kg Maximum power below 75kW
(102 CV)
81 81 81
Maximum power between 75 and 150 kW
(102 to 204 CV)
83 83 83
Maximum power equal or above 150 kW
(204 CV)
84 84 84

1) Vehicle designation according to NBR 6067
2) PTB: Total Gross Weight
3) Power: Maximum effective fluid power (NBR 5484)
4) This Table, published in Resolution 8 from Aug. 31, 1993, cancels and substitutes Table 1 of CONAMA Resolution 1 from December 11, 1993.
5) Complement provided by Resolution 242/98.

Vehicles with special characteristics and for use outside of roadways will have their limits increased by:

I – 1dbA for engines with power under 150kW.
II – 2dbA for engines with power equal or above 150kW.

§ 2 For all imported vehicles the maximum noise limits for vehicles in acceleration, established by this article, will be enforced from July 1 st , 1993, except for vehicles that fall under the Brazil/Argentine Bilateral Agreement (Protocol 21), and the maximum noise limits for these vehicles in acceleration established in this article will be enforced from January 1st, 1995.

§ 2 For all imported vehicles, the maximum noise limits for vehicles in acceleration established by this article will be enforced from March 1st, 1994, except for vehicles produced or assembled in Argentina, Paraguay and Uruguay, for these vehicles the maximum noise limits for vehicles in acceleration establishes by this article will be enforced from January 1st, 1995, for vehicles that are mentioned in item “a” of § 1 of this article from January 1 st 1996 and for all vehicles mentioned in item “b” of § 1 of this article. (new text provided by Resolution 8/93)

§ 3 The maximum noise limits established by this article must be respected during the entire granted warranty period and subjected to the conditions specified by the producer and/or importer.

§ 4 Eventual impossibilities to comply with the established percentages (%) included in the schedule will be
assessed by IBAMA.

§ 5 The noise levels of running but still vehicles is the value of reference of the new vehicle stated in by the verification process. This rate, added by 3 (three) dB(A),will be the inspection maximum noise limits for vehicles in circulation.

§ 6 IBAMA must be provided, from January 1st, 1994, two copies of the noise levels for running but still vehicles, measured near the exhaust pipes, in accordance with NBR-9714 for all produced models in order to allow for the inspection of vehicles in circulation.

§ 6 IBAMA must be provided, from March 1st, 1994, two copies of the noise levels for running but still vehicles, measured near the exhaust pipes, in accordance with NBR 9714 for all produced models in order to
allow for the inspection of vehicles in circulation. (new text provided by Resolution 8/93)

Art. 2. The tests for the measurement of noise levels for all purposes of this Resolution must be performed in
accordance with Brazilian standards NBR 8433 – Noise produced by accelerating motor vehicles, Test Method
and NBR 9714 – Noise produced by but still motor vehicles, Test method for the measurement of noise near the exhaust pipes.

Art. 2 The tests for the measurement of noise levels for all purposes of this Resolution must be performed in accordance with Brazilian standards NBR 8433 (1995) – Road motor vehicles in acceleration- ascertainment of noise level; and NBR 9714 (1999) – Road motor vehicles – Noise produced by running but still motor vehicles, in relation to the measurement collected near the exhaust pipes. The hardware used for the undertaking of noise level tests must be calibrated by INMETRO or an accredited laboratory that is part of the Brazilian Calibration Network (RBC) and the test locations must be inspected by IBAMA in order to obtain a Conformity Verification Statement. (new text provided by Resolution 272/00)

Single paragraph. The positioning of the microphone for the measurement of noise in the proximities of the exhaust pipes, according to NBR 9714, must be performed through the use of a meter according to the specifications described in annex D.

Art. 3 The exhaust system must be projected, produced and installed in the vehicle in a manner that will allow it to resist the normal vibrations and corrosion to which the vehicle is exposed and to allow for full compliance with the provisions set by this Resolution in normal use conditions. In cases when fibrous materials are used in exhaust systems that may not contain asbestos. The following measures must also be adopted in order to safeguard full compliance with the maximum noise levels established by this Resolution:

a) conditioning of fibrous materials in order to avoid direct contact between exhaust gases and these material; or
b) in cases when there is direct contact between exhaust gases and fibrous materials the exhaust system must be submitted to a conditioning before the inspection test, through a simulation of normal usage conditions, according to annex C, or by the simple removal of the fibrous materials from the silencer.

Art. 4 The main components of the exhaust system must contain non-delectable markings that identify the producer through its commercial brand.

Art. 5 The vehicle producer or its legal representative or the importer(s) must undertake the inspection of representative production prototypes before the start of production or the importation of vehicles.

§ 1 The individual responsible for the inspection of the prototype must have a certified and specialized team at his/her disposal who must keep a permanently actualized archive containing all documentation related to inspections undertaken during the pre-production/importation phase. IBAMA must be informed regarding the name and full address of the individual responsible for prototype inspections and his/her substitutes must be registered by IBAMA as well as any possible alterations to the standards.

§ 2 The establishment of noise levels for vehicles belonging to one and the same brand model may be performed through the testing of one single vehicle, considering the family master configuration and in accordance with the technical criteria specified in annex A.

§ 3 The inspection test reports related to prototype vehicle of all brand models and their respective master configurations must contain annex A of this Resolution and be forwarded to IBAMA before the production start date and/or enforcement dates for the respective maximum noise limits.

§ 4 Reports and tests undertaken outside of Brazil may be accepted at the discretion of IBAMA if it is not possible to perform prototype inspection tests within Brazil.

Art. 6 The inspection of prototypes is only valid for the respective model and year of production. However, vehicles that contain the same configuration as those previously verified/inspected, characterized by the respective annexes and under the same demands, it is allowed to use the same results and data and the manufacturer of the vehicle, or his/her legal representative or the importer(s) will assume full responsibility for the continuity of previously approved vehicle specifications.

Art. 7 In order to verify vehicle production conformity with the provisions set by this Resolution, the responsible for this verification may select random production line vehicle samples in order to perform tests, or vehicles from commercialization stocks.

§ 1 It is considered a sample a vehicle tested according to the standards established by article 2 of this Resolution.

§ 2 If the initially tested vehicle does not meet the required noise emission limits tests must be performed in a larger sample of vehicles through mutual agreement between the manufacturer and IBAMA, limited to between five and thirty vehicles with the same configuration and including the vehicle that was initially tested.

§ 2 If the tested vehicle’s sound level does not exceed more than 1 dB(A) of established rates the vehicle model will be considered as meeting the specifications set by the present Resolution. (new text provided by
Resolution 272/00)

§ 3 Production will be considered as adequate if it is performed according to the following conditions:

§ 3 If the tested vehicle does not fulfill the provisions set by the previous paragraph a further two vehicles of the same model will be tested. If the sound levels of the second and third tested vehicles exceed the limit by more than 1 dB(A) the vehicle model will be considered as lacking harmony with the provisions set by the current Resolution and the manufacturer must take the necessary measures in order to re-establish its conformity. (new text provided by Resolution 272/00)

X= arithmetical medium of obtained results, in all vehicles;
k = statistical factor established in Table 2;
n = number of sample vehicles;
Xi = each and every result reached according to NBR 8433;
Li = Maximum established noise level limits.

Table 2 – Statistical Factors

n 5 6 7 8 9 10 11 12
k 0,421 0,376 0,342 0,317 0,296 0,279 0,265 0,253
n 13 14 15 16 17 18 19
k 0,242 0,233 0,224 0,216 0,21 0,203 0,198

Note : If n ≥ 20 , K = 0,860/√n

Art. 8 The vehicle manufacturer or his/her legal representative or importer(s) must provide a model master configuration and a statistical procession production report. The report must be issued up to the fifth month after the start of commercialization or importation and thereafter annually, containing noise levels according to NBR 8433 and/or NBR 9714, at the discretion of the manufacturer, for vehicles randomly chosen and produced during the period of the corresponding report. This data must be archived during a two year period and provided to IBAMA whenever requested.

Single paragraph. The manufacturer may choose to use another quality production alternative method as long as it has been approved by IBAMA and with proved correlation with the noise levels emitted by the vehicle.

Art. 9 The vehicle manufacturer or his/her legal representative or importer(s) that find and spontaneously correct any non-conformity in the production of commercialized vehicles must inform IBAMA and forward a report on the adopted corrective measures.

Art. 10. IBAMA may request clarifications or the revision of reports at any given time and at its discretion, as long as duly justifiable, and request the performance of tests that confirm prototype inspections and production conformity and select, randomly, samples of vehicles from the assembly line or from commercialization stocks for the performance of tests.

Single paragraph. IBAMA must be provided with the means necessary for the performance of tests according to the provisions set by article 2 of this Resolution including calibrated measurement tools and their accessories, test fields and vehicles for testing purposes.

Art. 11. IBAMA may, in cases where irregularities have been verified during prototype testing processes or related to production conformity by the responsible enterprise, issue a Commercialization Suspension Order for the respective vehicle configurations.

§ 1 The Commercialization Suspension Order implies immediate compliance with its provisions until the irregularities that originated it have been clarified and corrected.

§ 2 The re-initiation of vehicle commercialization can only start after full compliance with the provisions set by this Resolution.

Art. 12. In cases related to product non-conformity the vehicle produce, his/her legal representative(s) or the importer(s) must, within 180 days counting from the date of verification, remedy all problems that have caused production non-conformity and recall and repair all vehicles with belonging to the same series and with the same configuration.

§ 1 The repairs must be undertaken by technical assistance services accredited by the manufacturer, his/her legal representative or by the importer, under their guidelines and responsibility.

§ 2 Production corrections and the repair of vehicles must be approved by IBAMA through the presentation of documentation that clearly describes adopted measures, the efficacy of the same and the number of involved vehicles.

§ 3 o Non-compliance with the provisions set by this article will imply the hindrance of the commercialization of the configuration(s) of the vehicle(s) in question or, when it has already been suspended, the responsible party will be subjected to administrative and legal sanctions.

Art. 13. From January 1 of 1994 all non-original parts and components of models that have proved conformity with the provisions set by this Resolution, which are integral parts of the exhaust system and produced for the replacement, may only be commercialized after meeting the same verification IBAMA demands by the manufacturer or importer of exhaust systems related to compliance with the provisions of this Resolution for products used in new vehicles. The maximum noise level of replacement exhaust systems in running but still vehicles must be the same as the one declared during the testing process of the prototype of the corresponding original model.

§ 1 The collected backpressure rate, according to annex E, cannot be above the one specifies in annex A, for original parts and components.

§ 2 IBAMA may select, for purposes related to product conformity with the demands placed by this Resolution, samples of exhaust systems randomly chosen form the assembly line and/or producer sto cks for the performance of tests. The process must follow the same procedures as those prescribed for the verification of conformity for new vehicles and in compliance with other paragraphs included in this article.

§ 3 Non-compliance with the provisions set by this article implies that the producer or his/her legal representative or the importers will not be allowed to commercialize the exhaust systems until they have been subjected to modifications according to the demands set by this Resolution.

Art. 14. The manuals of vehicles that have proved conformity with this Resolution must, from January 1, 1994, include the following information:

a) this vehicle is in conformity with current legislation related to the control of sound pollution for motor vehicles;
b) folder containing the maximum allowed noise limits for vehicles in circulation;
c) procedure specifications for the maintenance of the exhaust system (if applicable).

Art. 15. Expenses directly related to tests, verifications, product corrections, recalls for repairs and actual repair costs, including the cost of substituted components, are the responsibility of the producers and/or importers of vehicles and exhaust systems.

Art. 16 Producers, their legal representatives or importers must provide IBAMA with monthly sale reports, form January 1st 1994 and onwards, on the sale of all vehicle configurations commercialized within the National Territory.

Art. 17. The definitions provided by annex E are hereby established for all purposes of this Resolution.

Art. 18. IBAMA may enter into agreements, contracts and activities with organs and entities that may provide direct or indirect contribution for the development of this program as well as delegate competence foreseen by this Resolution to other organs.

Art. 19. Non-compliance with the provisions of this Resolution will subject offenders to penalties foreseen by Law 6.938 from Aug. 31, 1981 and the text provided by Law 7.804 from July 18, 1989 without prejudice to other possible penalties foreseen by federal legislation as well as penal and civil sanctions.

Art. 20. It is IBAMA’s duty to reach decisions on cases omitted by this resolution..

Art. 21. This Resolution shall enter into effect on the date of its publication and other pertinent standards will be enforced until time for the implementation of each of the stages of the schedule established by art. 1.




Note: Cases related to the production of vehicles through the use of bus chassis or rolling bus platform undercarriages, supplied by a third party, are covered by Annex 1 of Resolution 17/95.

1. Vehicle brand:
2. Vehicle Model/production year/ model:
2.1 – List of represented configurations:
2.2 – Total Gross Weight:(kg) – (except for cars and mixed usage derived vehicles derived from cars)
2.3 – Technical criteria for the definition of master configuration and presented configuration.
3. Name and address of chassis manufacturer:
4. Name and address of Legal Representative:
5. Name and address of the importer(s), if applicable:
6. Engine:
6.1 – Manufacturer:
6.2 – Type:
6.2.1 -Otto/ Diesel:
6.2.2 -Cycles: 2/3 Cycles
6.3 – Model:
6.4 – Maximum power: ______ ,(kW) to ___ (l/min) (rpm)
6.5 – Cylindrage: _______ (cm3 ) ______ (1)
7. Transmission:
7.1 – Gear box: manual/automatic
7.2 – Total number of gears (except back gear) including transmission ratios
8. Hardware/Materials:
8.1 – Exhaust system (sketch).
8.1.1 – Fibrous material in contact with gases: Yes/No
8.2 – Air intake silencer:
8.2.1 – Manufacturer:
8.3 – Catalytic converser (if applicable)
8.3.1 – Manufacturer:
8.4 – Tire designation (ABPA –Brazilian Tire and Hoops Association):
8.5 – Additional specifications deemed as necessary by the manufacturer in order to safeguard compliance with the provisions of this Resolution.
9. Measurements:
9.1. Noise levels in acceleration according to NBR 8433

Vehicle Identification Model: _________ Production year: _________
N.VIN: _________ Pot. Máx:_____(kW) PBT_____(kg)
Background Noise Level dB(A)
1st Measurement 2nd Measurement 3rd Measurement
Approximate speed (km/h) Angular speed (rpm) N.R. Right side
N.R. Left side
1st Meas. 2nd Meas. 1st Meas. 2nd Meas.
2nd gear
3rd gear
4the gear
5th gear
6th gear
Result _______________________________________________ dB(A)

Obs.: The rates registered for noise levels are the rates provided by the measurement minus 1 dB(A).

9.2. Noise levels while running but still according to NBR 9714.

Vehicle Identification Model: _________ Production year: _________
N. VIN/Series________
Background Noise Level dB(A)
1st Measurement 2nd Measurement 3rd Measurement
Rotation (rpm) Exhaust noise level dB(A)
1st measurement 2nd measurement 3rd measurement Arithmetic Medium
Result: ________________________________________________ dB(A)

9.3. Maximum allowable level of exhaust system backpressure (according to annex E): (______kPa) (_______mmHg).
9.4. Measured exhaust system backpressure: (______kPa) (_______ mmHg) (only applicable for manufacturers of non-original replacement parts and components)
10. Data on tested vehicle:
11. Test report data:
12. Test report number:
13. Location:
14. Date:
15. Name and signature of test manager:


ANNEX B – Definitions

1. Vehicle category : definitions according to NBR 6067;
2. Engine cylinders : amount of engine cylinders between the neutral superior and inferior points of the pistons measured in cubic centimeters or in liters;
3. Components and original parts: are those that form the production vehicle and those defined by the manufacturer as replacement parts;
4. Configuration : vehicles characterized by engines with the same amount of cylinders’, supply system, transmission type and ratio and equivalent exhaust systems;
5. Master configuration : configuration that represents the assembly and operational characteristics of the model/series of vehicles in production, in such a manner that no other vehicle of the same model/series will emit noises that differ from one vehicle to another;
6. HP(horse power): potency unit;
7. dB (A): unit of the pressure level in decibel, weighed by the frequency response curve in A, for the quantification of noise levels;
8. Models/series : group of configurations of similar vehicles in such a manner that the master configuration of the model/series shows results that prove compliance with maximum established noise levels for other configurations that compose the same;
9. kW (kilowatts ): power unit;
10. Maximum noise level for the inspection of vehicles in circulation: noise level while the vehicle is standing still, added by 3.0 (three) dB (A);
11. Fibrous materials : Materials composed of metal, ceramic or mineral fibers used for the fabrication of silencers;
12. Parts market : market for systems, parts and components for vehicles in use;
13. Two-stroke engine : engine with a two phase cycle (combustion-exhaust and intake-compression);
14. Four-stroke engine : engine with a four phase cycle (intake, compression, combustion and exhaust);
15. Total Gross Weight (TGW): weight stated by the manufacturer for specific operation conditions, based on material resistance assessments, tire load capacity, etc., according to NBR 6070;
16. Maximum power : maximum liquid effective potential according to NBR 5484;
17. Repair : system repairs, parts or components with defects or worn, with or without their substitution;
18. Silencer : vehicle component that reduces the noise produced by gas shocks with the environment, whose speed and intensity are gradually reduced by the flow of gases in its interior, may be included in more than one of the components of a vehicle;
19. Exhaust system : group of components that comprise the exhaust collector, exhaust pipe, discharge pipe,
expansion chamber(s), silencer(s) and catalytic conversor(s), when applicable
20. Similar vehicles : are vehicles of two, three or more wheels whose assembly and propulsion characteristics originate in motorcycles, scooters, mopeds or bicycles with auxiliary engines or are similar to these. They are examples of vehicles similar to motorized scooters, mopeds with a lateral car or load carts, etc.;
21. Production conformity verification : confirmation that the vehicles, or exhaust systems in the parts supply market, serially produced or not, are in harmony with the maximum established noise limits and other demands set by this Resolution;
22. Prototype Verification : testing of a pre-production commercial vehicle, characterized by the manufacturer as being the master configuration, which complies with the maximum noise levels, and other demands, established by this Resolution.


Simulations of normal usage conditions may be performed through one of the three tests that are described hereunder or by the simple removal of the fibrous materials from the silencer;

a) Field drill by 10.000 km;
a. 1) half of the tests must be performed in urban areas and the other half on high speed roads: continuous drills may be substituted by a test program on new lanes;
a.2) the two types of traffic should be alternated several times;
a.3) the full test program must also include a minimum of ten stops under a minimum period of three hours in order to allow for the reproduction of cooling effects and possible condensation effects;

b) Bench drill:
b. 1) the engines must be connected to a dynamometer and the exhaust system of the original vehicle installed according to manufacturer instructions;
b.2) the test must be performed in six periods during six hours with intervals of a minimum of twelve hours between periods in order to allow for the reproduction of cooling effects and possible condensations;
b.3) during each six hour period the engines should be running according to the following specifications:
1) five minutes in low gear;
2) one hour at 1/4 of the charge at 3/4 of total maximum power;
3) one hour at 1/2 of the charge at 3/4 of total maximum power;
4) tem minutes at full charge at 3/4 of total maximum power;
5) fifteen minutes at 1/2 of the charge of total maximum power;
6) Thirty minutes at 1/4 of the charge at maximum power rotation;
The total sequence duration from 1 to 6 is three hours which must be repeated in order to fulfill the total six hour period;
b.4) the silencer should not be refrigerated through forced air currents. However, if necessary, the silencer may be refrigerated in order not to exceed the maximum temperature, when the vehicle engines is running at maximum speed during the simulation;

c) pulse simulation:
c.1) the exhaust system should be installed in the vehicle or connected to the test engine. In the first case the vehicle must be tested in a roll dynamometer and in the second the motor it should be assembled on a dynamometer test bench. The test hardware, according to the presented sketch, must be connected to the exhaust gas exit pipe extremity. Other hardware combinations may be used as long as they reach equivalent results;
c.2) the tools must be adjusted in order to interrupt and re-establish the flow of gases, alternatively through a rapid action valve and during 2.500 cycles;
c.3) the valve must open when the backpressure measured at a minimum of 100mm at the beginning of the inlet flange reaches a rate of between 0.35 and 0.40 bar. It should close when the backpressure does not differ more than 10% of the stabilized rate with opened valve;
c.4) the retardation dispositive must be adjusted to the period that is the result of the conditions described in item c.3;
c.5) engine rotation rate must be 75% of the maximum rotation potential;
c.6) the power shown by the dynamometer must be 50% of the full charge potential measured at 75% of the maximum rotation potential;
c.7) all drains must be closed during tests;
c.8) the full test must be completed in a 48 hour period. If needed, a cooling period could be implemented every hour.


(LEGENDA – Opcional = Optional)
1 – Flange or entry glove for the connection of the exhaust pipe.
2 – Manual valve.
3 – Pressure compensator with a capacity of 35 to 40 liters.
4 – Pressure regulator with operation spectrum of 0.05 to 2.5 bar.
5 – Retardation device.
6 – Pulse meter.
7 – Rapid action valve operated through a pneumatic cylinder of 120 N to 4 bar. The feedback time, opening or closing, should not exceed 0.5 seconds.
8 – Exhauster.
9- Flexible hose.
10-Pressure meter.


ANNEX D – Gauge Instructions

1. The gauge for the measurement of noise is an auxiliary device that allows for the precise positioning of the microphone, according to NBR-9714. It is composed of a triangle with two supports (1), one for the positioning near the exhaust pipe and another for the positioning of the microphone. The third vertex possesses a limit aim (5). The device also possesses double bubble level(3).

2. Depending on the positioning of the exhaust system (left or right sides) one of the supports (1) must be positioned near the exhaust gas exit hole. The correct leveling of the hardware must be verified through the levels.

3. The aim (5) is used in order to achieve the correct visual alignment of the support (1) with the flow of gases.

4. The microphone is positioned on the other support (1).

5. In the case of vertical exhaust systems the support (1) must be equal to the diameter of the hole.

6. Depending on the exhaust diameter the supports may be larger than those shown in the sketch.

7. The device must be always used at a height, from the floor, equal or over 0.2 meters.


Legendas: 1. Encosto= Support /Steel material…thickness 2. Chapa de Compensado = Plywood Sheet/thickness 3. Nivel de bolha = Bubble level 4. Cantoneira = Corner/Steel sheet material…thickness 5. Mira para Balizamento = Limit Aim/Steel material…thickness
Fixação da Mira= Aim setting
Medida em milimetros = measured in millimeters

ANNEX E – Backpressure Measurring Points

máx = max. min=min. (PARA TOTAS AS FIGURAS)


Two interconnected measuring points in order to allow for a single reading

(1) If it is not possible, use Sketch 3

Note: Table 1 ratified by Official Gazette 201 on October 21, 1993, and was soon changed by the re-publishing of Resolution 8/93.

This text does not substitute the text published in the Official Gazette on Feb. 15, 1993.