The Ministry of Consumer Affairs, Food & Public Distribution, Government of India, has released draft rules concerning radar equipment for measuring vehicle speed. This article delves into the specifics of these regulations, including testing conditions, operational guidelines, and the process for stakeholder feedback.
The newly proposed rules outline stringent requirements for radar equipment used in measuring vehicle speed on roads. The regulations cover various aspects, from the correct operation of radars to the construction and reliability of electronic components.
One crucial aspect highlighted in the rules is the necessity for radars to ensure certainty in vehicle identification. This requirement aims to prevent errors in attributing speed measurements to the wrong vehicle, even in scenarios involving multiple vehicles passing simultaneously.
Moreover, the rules emphasize the importance of aiming devices, which control the angle of incidence of the radar beam. Strict tolerances are set to minimize measurement errors attributable to misalignment, ensuring accuracy in speed detection.
The regulations also address the radiation model of the radar antenna, outlining specifications for emitted power, receiver sensitivity, and beam angles. These parameters are crucial for maintaining accuracy in speed measurement across different traffic scenarios and environmental conditions.
Furthermore, the rules mandate the inclusion of recording devices in radars to document measurement results accurately. These records must include essential information such as date, time, measured speed, and vehicle direction, ensuring transparency and accountability in speed enforcement.
Additionally, the rules stipulate requirements for automatic and autonomous radar systems, necessitating a high level of confidence in measurement accuracy, especially in unattended operation scenarios.
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I-9/24/2024-W&M
Government of India
Ministry of Consumer Affairs, Food & Public Distribution
Department of Consumer Affairs
Legal Metrology Division
Krishi Bhawan, New Delhi-01
Dated: 13.5.2024
Subject– Draft Rules on Radar equipment for the measurement of the speed of vehicles for comments from stakeholders – reg.
Undersigned is directed to refer to the above mentioned subject and to state that the Draft Rules on Radar equipment for the measurement of the speed of vehicles, are placed in the website of the Department www.consumeraffairs.nic.in for seeking comments from all stakeholders by 11.06.2024. The comments may be sent to email-ID: dirwm-ca@nic.in/ ashutosh.agarwal13@nic.in/ mk.naik72@gov.in.
(Ashutosh Agarwal)
Director (Legal Metrology)
Ph: 011-23389489
Email: ashutosh.agarwal13@nic.in
To:
All concerned
GOVERNMENT OF INDIA
MINISTRY OF CONSUMER AFFAIRS, FOODAND PUBLIC DISTRIBUTION
(DEPARTMENT OF CONSUMER AFFAIRS)
New Delhi, the …………………… 2024
NOTIFICATION
GSR …………… In exercise of the powers conferred by sub-section (1) read with clauses (c), (f), (h), (i) and (s) of sub-section (2) of section 52 of the Legal Metrology Act 2009, (1 of 2010), the Central Government hereby makes the following rules, namely:-
1. Short title and commencement
(1) These rules may be called the Legal Metrology (General) (Amendment) Rules, 2024.
(2) They shall come into force from the date of publication of this notification in the Official Gazette, as follows:
(i) All the Radar equipment for the measurement of the speed of vehicles which will be installed after publication of this notification shall be verified and stamped within one year;
(ii) All the Radar equipment for the measurement of the speed of vehicles which are already installed at the time of publication of this notification shall be verified and stamped as and when their re-verification shall become due.
(iii) All the Radar equipment for the measurement of the speed of vehicles which are already installed at the time of publication of this notification and their re-verification has already become due or will become due during next one year shall be verified and stamped within one year.
2. In the index of the Schedule of the Legal Metrology (General) Rules, 2011 under the Eight Schedule after Part X, the entries “Part XI”, “Radar equipment for the measurement of the speed of vehicles” shall be inserted.
3. In the Legal Metrology (General) Rules, 2011, (herein after referred to as the said rules), under the Eight Schedule the Part XI and the entries made thereunder, the following shall be inserted, namely.
EIGHTH SCHEDULE
SPECIFICATIONS FOR MEASURING INSTRUMENTS
PART XI – RADAR EQUIPMENT FOR THE MEASUREMENT OF THE SPEED OF VEHICLES
1. Scope
This rule is applicable to microwave Doppler radar equipment for the measurement of traffic speed on roads, hereafter, in short, “radar”. The radar shall satisfy the conditions prescribed in these rules when the results of measurement are to be used in legal proceedings.
2. Rules of correct operation
(1) Radars shall be installed and used in accordance with the instructions approved with the instrument, at the time of model approval.
(2) Certainty of vehicle identification
The construction of the radar, including the internal logic of the measurement process, shall ensure that, when the instrument is used in accordance with the instructions approved with the instrument, at the time of model approval, an indicated speed cannot be attributed to the wrong vehicle even where vehicles are passing or overtaking, or when the radar is mounted on a moving vehicle. The radar shall have a direction discriminator. However, because of its limited effect and stability, a direction discriminator (single sideband device) does not offer a complete solution; additional means shall be used. Where there is no other solution, the radar shall invalidate its own result when two vehicles with different speeds pass simultaneously through the radiation beam.
(3) Aiming device
The angle of incidence of the beam shall be controllable by means of an aiming device so that relative errors of measurement attributable to misalignment are not greater than ± 0.5 %. The angle shall be stable. The aiming device may be omitted if the radar is to be used with a beam that is practically parallel to the direction of traffic movement (incidence angles not exceeding 10°). The instructions approved with the instrument, at the time of model approval, shall give details for positioning and adjustment, for all foreseeable installations (roadside, bridges, patrol cars, prepared semipermanent sites, etc).
(4) Radiation model of antenna
The approval of a given angle of incidence is as mentioned in the instructions approved with the instrument, at the time of model approval. For beam axes not parallel to the direction of traffic movement, angles of 15° to 30° are recommended.
When the radar is installed and used in accordance with the instructions approved with the instrument, at the time of model approval, no measurement shall be possible in those parts of the antenna lobe where an incorrect angle of incidence may result in relative measurement errors greater than ± 2 %. Errors resulting from a tilting of the radar in relation to the surface of the road shall also be considered. sodium) passes from air into the oil or fat.
Note: This requirement may be satisfied by signal processing or by special shaping of the radiation model. (For example, at an angle of incidence of 22°, an attenuation of any side lobe to − 15 dB, or − 30 dB after reflexion, together with a total main-lobe width of less than 12° at − 10 dB, may give satisfactory results).
The emitted power and the receiver sensitivity shall be matched in such a way that, in normal operation, measurements across more than two lanes (i.e., from the third lane) occur rarely. If in special situations longer ranges must be activated, the fact shall be stated in writing near the indicating device and on any records produced.
(5) Time span for indication
If it is possible to use the radar without a suitable recording system (see clause 2(6)), the visual indication of speed shall remain visible and shall inhibit any further measurement until it is freed by a positive action. No event or action during this time may influence the result or have any effect on subsequent measurements. These requirements need not apply to results below a given speed limit.
If the indication is of the analog type, it may not drift by more than 1 km/h in 5 minutes.
(6) Recording devices
If the radar records the results of measurement, the record shall indicate the date and time of the measurement, the measured speed and the vehicle’s direction of travel. It shall be possible to discover from the record the sensitivity setting of the radar (see clause 2(4)). If the identity of the vehicle is not made recognizable by a photograph, records shall provide for its immediate identification in writing. The fact that checks as stated in clause 2(9) have been performed shall be evident from the records. The requirements of clause 2(2) shall be fulfilled.
If a camera is used, the correct relationship between the direction of radiation and that of the optical axis of the camera shall be ensured by positive mechanical links or by the operations described in the instructions approved with the instrument, at the time of model approval by which the correct aiming of the system is verified from pictures.
(7) Automatic and autonomous radar
Radars designed for operation under circumstances where it is not possible for an officer to verify continuously their satisfactory performance shall provide a level of confidence “near to certainty” that the error of each transmitted result shall be within the permissible limits. The manufacturer shall explain in the instructions approved with the instrument, at the time of model approval, the measures he has taken to satisfy that condition.
The level of confidence shall take account of uncertainties of measurement, as well as a possible single failure in the whole instrument. It shall be confirmed by the model approval authority. If estimated by statistical methods, it shall be at least 99.8 % (see also clause 7(3)).
Note: The permanent automatic checking of the instrument’s essential operations is required in clause 3(4)(ii) of this rule. Furthermore, with such unattended operation it is strongly advised that redundant measurement techniques such as, for example, taking two pictures of the vehicle separated by a specified time interval be used.
(8) Automatic exclusion of inaccurate results when the power voltage varies
Speed indications shall be inhibited when the power voltage varies beyond limits at which the allowable errors may be surpassed.
(9) Overall function test device
The radar shall incorporate some means of simulating a measurement that is independent of the measuring circuits, and by which, at switch-on and additionally at the operator’s will, the instrument is checked overall. Such means shall make evident at least every nonintermittent failure of the low-frequency and result-handling circuits, including circuits necessary to satisfy clause 3(4)(ii) and including the functioning and accuracy of indication. Records shall confirm that these tests have been performed.
These requirements need not apply if undetected intermittent or permanent failures can be excluded (see clause 3(4)(ii)).
Notes: (i). For discontinuous (digital) signal handling channels, clause 3(4)(ii)(a) prescribes protective measures sufficient to ensure correct operation.
(ii). Analog channels may be checked by, for example, simulated Doppler signals injected near the output of the demodulator stage, or by a device modulating the microwave signal. Such means to verify, among other things, that the upper and lower sensitivity limits are correct, may be omitted if model approval tests show that variations of those limits are detected in another way or cannot influence measurement results (see clause 3(4)(ii)(b)(bb)) and that the signal is reliably transformed into a speed indication.
3. Construction
(1) Indicators and speed range
In radars useable without data recording, the indicators shall be readable by two operators simultaneously in lighting conditions corresponding to the conditions of use for which the instrument is suitable according to the instructions approved with the instrument, at the time of model approval.
The speed range shall include at least the range (30 km/h, 150 km/h).
(2) Mechanical strength
The radar shall be well and solidly built. The materials shall be chosen to ensure sufficient strength and stability.
(3) Resistance to extremes of climate
(i) When out of service, radars shall be capable of withstanding ambient temperatures of − 25°C to + 70°C.
The manufacturer shall indicate the ambient temperature limits between which the radar will operate with errors within the permitted limits. When these temperature limits are passed, radars designed for unattended operation shall automatically go out of service. The range shall include at least the range (0°C, + 50°C) (see clause 7(1)(i).
(ii) The radar shall be insensitive to relative humidity of the ambient air, both under static conditions of storage and in service as described in clause 3(3)(i) (For insensitivity to condensation, see Annex, clause 2(2)).
(iii) The parts of the radar that are exposed to the weather shall be dust proof and splash proof when all accessories are fixed.
(4) Reliability of electronic and logical components
(i) Reaction to disturbance
Radars shall undergo tests showing their reactions to:
– power line variations,
– electrical bursts on the power line,
– external electromagnetic fields.
The relevant tests, severities and criteria for acceptance shall be as stipulated in the Annex to this rule.
(ii) Protection against electronic failure
(a) Discontinuous (digital) signals
(aa) Results conveyed by digital signals (transfer operations, logic operations, storage, indications, etc.) shall be made secure by additional logic-checking operations, individually (step by step) or collectively (overall). Any discrepancy shall block the measurement in process.
(ab) Elements and components used in such operations (program memories, transfer memories, processors, cabling, indicators, etc.) shall be implicitly checked at least every time the equipment is switched on, by special checking operations, unless they are checked automatically by the logical measures mentioned in clause 3(4)(ii)(a)(A).
Errors of function that may be made evident as logical signals shall inhibit further measurement. Others (e.g., indicator errors) shall be clearly indicated and the instructions approved with the instrument, at the time of model approval shall explain the measures to be taken.
(ac) Instructions (programs) and permanently stored data (e.g., scale factors, decision criteria, etc.) shall be checked at least every time the instrument is switched on, by methods that show that they are complete.
Note: Methods applicable to digital signals have following provisions:
A. All relevant measurement data shall be checked for correct value whenever they are stored internally or transmitted to peripherals via an interface, by such means as: parity bit, check sum, double storage, or handshake-routine with retransmission.
B. Upon switch-on (in the case of instruments permanently connected to the mains: at switch-on of indication), a special procedure shall be performed which shows all relevant signs of the indicator in their active and non-active state sufficiently long to be checked by the operator.
(C) Upon switch-on (in the case of instruments permanently connected to the mains: at switch-on of indication), all data storage components shall be checked automatically to verify that:
C.1 All procedures of internal transfer and storage of data relevant to the measurement result are performed correctly, by such means as:
– write-read routines,
– conversion and reconversion of codes,
– use of “safe coding” (check sum, parity bit),
– double storage,
C.2 The values of all permanently memorized instructions and data are correct, by such means as:
– summing of all instruction and data codes and comparing the sum with a fixed value,
– line and column parity bits (LRC and VRC),
The use of:
– cyclic redundancy check (CRC),
– double storage of data, both in same code,
– double storage of data, second in inverse or shifted coding,
– storage of data in “safe coding”, for example protected by check sum, line and column parity bits, when verified by the type approval tests, is considered as satisfying C.2.
The use of parity bit alone is not sufficient where data are stored or read and are relevant to the metrological characteristics of the instrument.
(b). Continuous signals (analogue signals)
(ba) Micro-wave circuits shall ensure a long-term stability of tuning (2 years) of approximately ± 0.2 % in frequency.
(bb) The gain of analogue channels shall have no influence on results, or its effects shall be periodically checked [see clause 2(9)].
4. Operation of the instrument
The manufacturer shall provide each radar with instructions approved with the instrument, at the time of model approval [see clause 2(1)]. These instructions shall contain at least: – the theory of operation of the equipment, – an explanation of the general operating schematic, – an accurate specification of normal operating conditions, – the modes of operation, – information on the principal causes of errors, – a review of the influence quantities affecting the measurements, and of the partial errors they may induce, – for radars designed to work without an operator, the information required in clause 2(7).
5. Protection against tampering
It shall be possible to seal or otherwise protect those parts which, if tampered with, could lead to errors in measurement or to metrologically unreliable operation.
6. Identification of the equipment
The instrument, or each separately housed subunit, shall carry, in indelible lettering, the following indications:
– the name (or trade mark) and address of the manufacturer or his representative,
– the type indication and serial number of the instrument,
– an indication of necessary connecting units by type number and, if not interchangeable, by serial number.
7. Model approval
(1) Metrological tests in the laboratory
Sure, here’s the information presented in a table format:
| (i) Test Conditions | Reference Value | Range |
| Ambient Temperature | + 20°C | -20°C to +60°C (1) |
| Ambient Humidity | 60% | Either value, non-condensing |
| Power Voltage | Nominal | -10% to +20% of nominal at least (2) |
| Frequency (if applicable) | Nominal | Nominal ± 3% |
| Length of Time Since Switched On | – | Radars shall be tested at +20°C and at minimum and maximum applicable temperatures |
Radars shall be tested at + 20 °C and at minimum and maximum applicable temperatures with 7 different power voltages; humidity and power frequency shall be varied only if they have a noticeable influence.
For each factor mentioned above, its variation throughout the whole defined range shall not induce a change of indication greater than 50 % of the moduli of the maximum permissible errors given in clauses 7(1)(ii) and 7(1)(iii).
| (ii) Testing of Micro-Wave Section | Requirements |
| Radiation Model and Power Limitation | Requirements of clause 2(4) apply |
| Aiming Device | Requirements of clause 2(3) apply |
| Frequency Range and Oscillator Stability | As mentioned in instructions approved with the instrument, at the time of model approval |
Note: Model approval is also dependent on certification by the authority for communications equipment.
(iii) Testing of the low-frequency section
From the frequency fd of the simulated Doppler signal the theorical speed indication shall be computed thus:
vd = 0.5 × fd × λ /cos α
where: λ = the emitted wavelength
α = the average effective angle of incidence (3)
All errors of indication (referred to vd) under reference conditions shall be less than ± 1 km/h, or ± 1% at speeds above 100 km/h.
For instruments with digital indication, fd shall be varied until the average switching (rounding) point is found, which shall be presumed to be halfway in value between the two neighboring indications. If, in fact, fractions of the least significant digit are discounted (rounding down), this is to be considered as an average scale shift.
(iv) Neither attenuation to the limit of reception of the signal mentioned in clause 7(1)(iii) nor limitations of its duration shall provoke errors greater than those prescribed in clause 7(1)(iii).
(v) Discriminating circuits, preliminary tests
Functions mentioned in clauses 2(2), 2(5), 2(8) and (if applicable) 2(4) and 2(7) shall be tested using the following procedures:
– lowering the power voltage below the limit of 90 % nominal, to the point of automatic cut-off (clause 2(8)),
– sweeping the frequency fd (clause 7(1)(iii)), mixing of two such frequencies, feeding them to the circuits with interruptions or in bursts
Specific values of frequency cannot be given, due to differences in emitter frequencies and beam widths. A frequency step corresponding to the arrival of a second vehicle with a speed difference of 3.5 km/h or more (3.5 % or more at speeds above 100 km/h) shall inhibit the output of a result, or the lower speed shall be output.
Brief frequency variations, simulating measurement instabilities, shall inhibit the output when their influence on the result can be more than 2 km/h (or more than 2 % at speeds above 100 km/h).
Further tests will result from the tests of electronic and logical components (clauses 7(2) and 3(4)) which will be affected in the following stage.
(2) Tests of effects of influence factors and disturbances
The tests that shall be performed and the criteria of acceptance are described in the Annex.
(3) Metrological field tests (to be performed after the tests of clause 7(2))
The metrological tests shall be completed by an operating test in actual traffic. This overall study of possible errors seems indispensable due to the complexity of factors affecting the result of a measurement (shape of antenna lobe, lateral distance between radar and passing vehicle, reflection characteristics of the latter, change of lane during passage through beam, braking, delays in measurement due to the presence of more than one vehicle, etc).
The error distribution shall be determined under conditions of variable speed and traffic density, and if possible, at various temperatures.
The average error of all results shall be within ± 1 km/h.
For model approval, 500 measurements shall be made, of which none shall give a positive error larger than + 3 km/h (or + 3 % at speeds above 100 km/h). Results that are recognizable as faulty by any user familiar with the instructions approved with the instrument, at the time of model approval shall be discounted.
If fewer measurements are made, they are to be considered as a sample which, by its result, shall validate the same error limits as would 500 measurements.
For autonomous radars, the results shall confirm the level of confidence required (see clause 2(7)).
The measuring system used for comparison shall have an uncertainty better than one third of that of the radar under test; 99.8 % of its results should have errors that are within ± 1 km/h (or ± 1 % at speeds above 100 km/h).
(4) Conformity to approved model
The approved model is defined by the instrument’s characteristics determining its metrological integrity.
As long as the metrological integrity depends on internal logical protections, the origin of the electronic elements is not so important. On the contrary, the structure of the checking circuits, the way in which they function and the programs which control them are important and are to be maintained in instruments manufactured according to an approved model. In consequence:
– the manufacturer shall submit details of the instrument’s logic,
– he shall disclose and discuss with the metrology services all changes in the approved model in this regard,
– the relevant services shall develop and maintain a safe storage system for such information; one solution is to sign the documents submitted and place them in the custody of the manufacturer or his representative.
ANNEX
TESTS OF EFFECTS OF INFLUENCE FACTORS AND DISTURBANCES
(wherever required IS Standards/ International Standards/ OIML Recommendations/ Documents
may be used for test methods/ procedures)
These tests are listed in the order of the requirements of this rule to which they relate.
Durability tests have been omitted because of the extent of internal logic protection required by this rule.
1. Mechanical strength test (clause 3(2) of the rule)
Mechanical shock
The radar is tilted about one bottom edge with a height of the opposite edge of 50 mm and then allowed to fall freely. The test requires one fall about each bottom edge.
After the test, a check as per clause 7(1)(ii) shall be performed (frequency and variations in radiated power).
2. Climatic resistance test (clause 3(3) of the rule)
(1) Dry heat – cold
The test simulates storage conditions, with the exception that the radar shall be mounted on a tripod to provide maximum exposure.
The dry heat test shall have a duration of 2 hours at 70 °C, the cold test 2 hours at − 25 °C, the radar being out of service.
After each test a check of the oscillator frequency (clause 7(1)(ii)) and a check of the conversion factor of the indication (clause 7(1)(iii)) shall be performed.
(2) Damp heat, condensing Immediately following the cold test, those parts of the radar which in normal use may be exposed to cold (other parts may be protected by closed plastic bags) shall be placed in a room at + 20 °C, with a humidity of about 80 %. The radar shall be put into the operating state and switched on for one hour after leaving the cold chamber. Partial checks in accordance with clauses 7(1)(ii) (radiation power), 7(1)(iii) (accuracy) and 7(1)(iv) (sensitivity) shall show that no incorrect indications result from condensation.
(3) Water splash test for parts exposed to water One bucket of about 10 litres of water shall be thrown from a distance of 3 m against each side of the radar, once from above and once from below, with the instrument in operation.
Checks according to clauses 7(1)(ii) (power) and 7(1)(iii) (accuracy) shall show that the water splashes have no effect. The radar shall be inspected to check that no water has entered it.
3. Tests of reliability of electronic and logical components (clause 3(4) of the rule)
(1) Power variations for battery-powered radars: see clause 7(1)(i).
(2) Bursts
Bursts of voltage spikes are superimposed on the mains voltage, with an amplitude of 1 kV, throughout the time necessary to simulate five speed measurements.
Checks according to clause 7(1)(iii) (accuracy) shall show either that the result corresponds to fd or that the indication disappears.
(3) Electromagnetic susceptibility
The radar is exposed to an electromagnetic field strength of 10 V/m at frequencies between 27 MHz and 500 MHz and of 3 V/m at frequencies between 500 MHz and 1000 MHz, the amplitude modulation being at a frequency which corresponds to the Doppler frequency for a speed of 60 km/h.
Checks shall be performed according to clauses 7(1)(iii) (accuracy), 7(1)(iv) (sensitivity) and 7(1)(v) (discrimination of speed variations and of the presence of more than one vehicle).
After completion of all the tests of the effects of influence factors and disturbances, all the tests of clause 7(1) of the rule shall be repeated with a suitable subset of characteristics to determine deviations from the initial intrinsic error.
[File No. WM-9(24)/2024]
(Anupam Mishra)
Joint Secretary to the Government of India
Note:- The principal rules were published in the Gazette of India, Extraordinary, Part II, Section 3, Sub-section (i), vide notification number G.S.R.71(E), dated the 7th February, 2011 and was last amended, vide notification number G.S.R. 763 (E), dated the 4th October, 2022.
Notes:
(1) This range is for parts installed outdoors; for parts installed in cars or shelters, the range is defined by the manufacturer and shall include at least the range (0°C, + 50°C).
(2) The lower limit shall be the switch-off point as defined in clause 2(8).
(3) This angle may be different from the geometric angle between beam axis and street direction, as a vehicle’s speed may sometimes be measured shortly after the vehicle enters the beam, or – due to delaying actions of discriminating circuits, for instance – after it passing the beam axis. The resulting average is different for traffic entering the beam from behind or from the front. If the manufacturer wishes such differences to be considered he shall indicate the appropriate average values to be used in the computation.
