The Measuring Instruments (Exhaust Gas Analysers) Regulations 2006 (revoked)

Regulation 2(1)

SCHEDULE 1 U.K. ESSENTIAL REQUIREMENTS

1.  The essential requirements are the relevant requirements relating to exhaust gas analysers contained in Annex I and Annex MI-010 set out in this Schedule. U.K.

Definitions U.K.

2.  In these Regulations—

“climatic environments” means the conditions in which exhaust gas analysers may be used;

“critical change value” means the value at which the change in the measurement result is considered undesirable;

“disturbance” means an influence quantity having a value within the limits specified in the appropriate requirement but outside the specified rating conditions of the exhaust gas analyser. An influence quantity is a disturbance if for that influence quantity the rated operating conditions are not specified.

“exhaust gas components” means the components determined by an exhaust gas analyser, namely—

(a)

carbon monoxide (CO);

(b)

carbon dioxide (CO₂);

(c)

oxygen (O₂); and

(d)

hydrocarbons (HC) of which the content has to be expressed as concentration of n-hexane (C₆H₁₄), measured with near-infrared absorption techniques, and

the volume fractions of the gas components are expressed as a percentage (%vol) for CO, CO₂ and O₂ and in parts per million (ppm vol);

“influence quantity” means a quantity that is not the measurand but that affects the result of measurement;

“lambda” means a dimensionless value representative of the burning efficiency of an engine in terms of air/fuel ratio in the exhaust gases;

“measurand” means the particular quantity subject to measurement; and

“rated operating conditions” mean the values for the measurand and influence quantities making up the normal working conditions of an exhaust gas analyser.

Allowable Errors U.K.

3.—(1) Under rated operating conditions and in the absence of a disturbance, the error of measurement shall not exceed the maximum permissible error (MPE) value as set out in paragraph 17.

(2) Unless stated otherwise, MPE is expressed as a bilateral value of the deviation from the true measurement value.

(3) Under rated operating conditions and in the presence of a disturbance, the performance requirement shall be as set out in paragraph 18(2).

(4) Where the exhaust gas analyser is intended to be used in a specified permanent continuous electromagnetic field the permitted performance during the radiated electromagnetic field-amplitude modulated test shall be within MPE.

(5) The manufacturer shall specify the climatic, mechanical and electromagnetic environments in which the exhaust gas analyser is intended to be used, power supply and other influence quantities likely to affect its accuracy, taking account of the requirements in this Schedule.

(a) Climatic environments—

The manufacturer shall the temperature range. The minimum temperature range is 30°C and shall be within the upper temperature limit of 70°C and the lower temperature limit of -40°C. The manufacturer shall indicate whether the exhaust gas analyser is designed for condensing or non-condensing humidity as well as the intended location for the instrument, that is open or closed.

(b) Mechanical environments—

(i) M1: This class applies to exhaust gas analysers used in locations with vibration and shocks of low significance, for example for instruments fastened to light supporting structures subject to negligible vibrations and shocks transmitted from local blasting or pile-driving activities and slamming doors.

(ii) The following influence quantities shall be considered in relation with mechanical environments—

(aa) vibration;

(bb) mechanical shock.

(c) Electromagnetic environments—

(i) Electromagnetic environments are classified into classes E1 and E2, as follows—

E1: This class applies to exhaust gas analysers used in locations with electromagnetic disturbances corresponding to those likely to be found in residential, commercial and light industrial buildings.

E2: This class applies to exhaust gas analysers used in locations with electromagnetic disturbances corresponding to those likely to be found in other industrial buildings.

(ii) The following influence quantities shall be considered in relation with electromagnetic environments—

(aa) voltage interruptions;

(bb) short voltage reductions;

(cc) voltage transients on supply lines and/or signal lines;

(dd) electrostatic discharges;

(ee) radio frequency electromagnetic fields;

(ff) conducted radio frequency electromagnetic fields on supply lines and/or signal lines;

(gg) surges on supply lines or signal lines or both.

(6) Other influence quantities to be considered, where appropriate, are—

(a) voltage variation;

(b) mains frequency variation;

(c) power frequency magnetic fields;

(d) any other quantity likely to influence in a significant way the accuracy of the exhaust gas analyser.

(7) When carrying out the tests as envisaged in these Regulations, the following paragraphs apply—

(a) The basic rules for testing and the determination of errors are—

(i) the essential requirements specified in sub-paragraphs (1) to (4) shall be verified for each relevant influence quantity. These essential requirements apply when each influence quantity is applied and its effect evaluated separately, all other influence quantities being kept relatively constant at their reference value; and

(ii) the metrological tests shall be carried out during or after the application of the influence quantity, whichever condition corresponds to the normal operational status of the exhaust gas analyser when that influence quantity is likely to occur.

(b) In relation to ambient humidity—

(i) according to the climatic operating environment in which the exhaust gas analyser is intended to be used either the damp heat-steady state (non-condensing) or damp heat cyclic (condensing) test may be appropriate; and

(ii) the damp heat cyclic test is appropriate where condensation is important or when penetration of vapour will be accelerated by the effect of breathing. In conditions where non-condensing humidity is a factor the damp-heat steady state is appropriate.

Reproducibility U.K.

4.  The application of the same measurand in a different location or by a different user, all other conditions being the same, shall result in the close agreement of successive measurements. The difference between the measurement results shall be small when compared with the MPE.

Repeatability U.K.

5.  The application of the same measurand under the same conditions of measurement shall result in the close agreement of successive measurements. The difference between the measurement results shall be small when compared with the MPE.

Discrimination and Sensitivity U.K.

6.  An exhaust gas analyser shall be sufficiently sensitive and the discrimination threshold shall be sufficiently low for the intended measurement task.

Durability U.K.

7.  An exhaust gas analyser shall be designed to maintain an adequate stability of its metrological characteristics over a period of time estimated by the manufacturer, provided that it is properly installed, maintained and used according to the manufacturer's instruction when in the environmental conditions for which it is intended.

Reliability U.K.

8.  An exhaust gas analyser shall be designed to reduce as far as possible the effect of a defect that would lead to an inaccurate measurement result, unless the presence of such a defect is obvious.

Suitability U.K.

9.—(1) An exhaust gas analyser shall have no feature likely to facilitate fraudulent use, whereas possibilities for unintentional misuse shall be minimal.

(2) An exhaust gas analyser shall be suitable for its intended use taking account of the practical working conditions and shall not require unreasonable demands of the user in order to obtain a correct measurement result.

(3) Where an exhaust gas analyser is designed for the measurement of values of the measurand that are constant over time, the instrument shall be insensitive to small fluctuations of the value of the measurand, or shall take appropriate action.

(4) An exhaust gas analyser shall be robust and its materials of construction shall be suitable for the conditions in which it is intended to be used.

(5) An exhaust gas analyser shall be designed so as to allow the control of the measuring tasks after the instrument has been placed on the market and put into use. If necessary, special equipment or software for this control shall be part of the instrument. The test procedure shall be described in the operation manual.

(6) When an exhaust gas analyser has associated software which provides other functions besides the measuring function, the software that is critical for the metrological characteristics shall be identifiable and shall not be inadmissibly influenced by the associated software.

Protection against corruption U.K.

10.—(1) The metrological characteristics of an exhaust gas analyser shall not be influenced in any inadmissible way by the connection to it of another device, by any feature of the connected device itself or by any remote device that communicates with the instrument.

(2) A hardware component that is critical for metrological characteristics shall be designed so that it can be secured. Security measures foreseen shall provide for evidence of an intervention.

(3) Software that is critical for metrological characteristics shall be identified as such and shall be secured.

(4) Software identification shall be easily provided by the exhaust gas analyser.

(5) Evidence of a software intervention shall be available for a reasonable period of time.

(6) Measurement data, software that is critical for measurement characteristics and metrologically important parameters stored or transmitted shall be adequately protected against accidental or intentional corruption.

Information to be borne by and to accompany the exhaust gas analyser U.K.

11.—(1) An exhaust gas analyser shall bear the following inscriptions—

(a) manufacturer's mark or name;

(b) information in respect of its accuracy,

plus, when applicable:

(c) information in respect of the conditions of use;

(d) measuring capacity;

(e) measuring range;

(f) identity marking;

(g) number of the EC-type examination certificate or the EC design examination certificate;

(h) information whether or not additional devices providing metrological results comply with these Regulations.

(2) The exhaust gas analyser shall be accompanied by information on its operation, unless the simplicity of the instrument makes this unnecessary. Information shall be easily understandable and shall include where relevant—

(a) rated operating conditions;

(b) mechanical and electromagnetic environment classes;

(c) the upper and lower temperature limit, whether condensation is possible or not, open or closed location;

(d) instructions by installation, maintenance, repairs, permissible adjustments;

(e) instructions for correct operation and any special conditions of use;

(f) conditions for compatibility with interfaces or other measuring instrument.

(3) Groups of identical exhaust gas analysers used in the same location do not necessarily require individual instruction manuals.

(4) The scale interval for a measured value shall be in the form 1 x 10ⁿ, 2 x 10ⁿ or 5 x 10ⁿ, where n is any integer or zero. The unit of measurement or its symbol shall be shown close to the numerical value.

(5) The units of measurement used and their symbols shall be in accordance with the provisions of Community legislation on units of measurement and their symbols.

(6) All marks and inscriptions required under any requirement shall be clear, non-erasable, unambiguous and non-transferable.

Indication of result U.K.

12.—(1) Indication of the result shall be by means of a display or hard copy.

(2) The indication of any result shall be clear and unambiguous and accompanied by such marks and inscriptions necessary to inform the user of the significance of the result. Easy reading of the presented result shall be permitted under normal conditions of use. Additional indications may be shown provided they cannot be confused with the metrologically controlled indications.

(3) In the case of hard copy the print or record shall also be easily legible and non-erasable.

Further processing of data to conclude the trading transaction U.K.

13.—(1) An exhaust gas analyser shall record by a durable means the measurement result accompanied by information to identify the particular transaction, when—

(a) the measurement is non-repeatable; and

(b) the exhaust gas analyser is normally intended for use in the absence of one of the trading parties.

(2) Additionally, a durable proof of the measurement result and the information to identify the transaction shall be available on request at the time the measurement is concluded.

Conformity evaluation U.K.

14.  An exhaust gas analyser shall be designed so as to allow ready evaluation of its conformity with the appropriate requirements of these Regulations.

Instrument Classes U.K.

15.  There are two classes (0 and 1) being defined for exhaust gas analysers and the relevant minimum measuring ranges for these classes are shown in Table 1.

Table 1

Classes and measuring ranges

Parameter	Classes 0 and 1
CO fraction	from 0 to 5 % vol
CO2 fraction	from 0 to 16 % vol
HC fraction	from 0 to 2 000 ppm vol
O2 fraction	from 0 to 21 % vol
λ	From 0.8 to 1.2

Rated operating conditions U.K.

16.—(1) The values of the operating conditions shall be specified by the manufacturer, as follows.

(2) For the electrical power influence quantities, the limits of the DC voltage supply.

(3) For the ambient pressure, the minimum and the maximum values of the ambient pressure are for both classes: _Pmin �?� 860 hPa, _Pmax ≥ 1 060 hPa.

MPE U.K.

17.  The MPEs are defined as follows—

(a) for each of the fractions measured, the maximum error value permitted under rated operating conditions according to paragraph 3(1) and (2) of this Schedule is the greater of the two values for the relevant class shown in Table 2, with absolute values being expressed in % vol or ppm vol, percentage values are percent of the true value;

Table 2

MPEs

Parameter	Class 0	Class 1
CO fraction	±0.03 % vol	±0.06 % vol
	± 5 %	± 5 %
CO2 fraction	±0.05 % vol	± 0.5 % vol
	± 5 %	± 5 %
HC fraction	± 10 ppm vol	± 12 ppm vol
	± 5 %	± 5 %
O2 fraction	± 0.1 % vol	± 0.1 % vol
	± 5 %	± 5 %

(b) the MPE on lambda calculation is 0.3 %. The conventional true value is calculated according to the formula defined in point 5.3.7.3 of Annex 1 of 98/69/EC of the European Parliament and the Council relating to measures to be taken against air pollution by emissions from motor vehicles and amending Council Directive 70/220/EEC M1 ; and

(c) for this purpose, the values displayed by the instrument are used for calculation.

Permissible effect of disturbance U.K.

18.—(1) For each of the volume fractions measured by the instrument, the critical change value is equal to the MPE for the parameter concerned.

(2) The effect of an electromagnetic disturbance shall be such that either—

(a) the change in the measurement result is not greater than the critical change value laid down in sub-paragraph (1); or

(b) the presentation of the measurement result is such that it cannot be taken for a valid result.

Other requirements U.K.

19.—(1) The resolution shall be equal to or of one order of magnitude higher than the values shown in Table 3.

Table 3

Resolution

	CO	CO 2	O 2	HC
Class 0 and class 1	0.01 % vol	0.1 % vol	(1)	1 ppm vol
(1) 0.01 % vol for measurand values below or equal to 4 % vol, otherwise 0.1 % vol.

The lambda value shall be displayed with a resolution of 0.001.

(2) The standard deviation of 20 measurements shall not be greater than one third of the modulus of the MPE for each applicable gas volume fraction.

(3) For measuring CO, CO₂ and HC, the instrument, including the specified gas handling system, must indicate 95 % of the final value as determined with calibration gases within 15 seconds after changing from a gas with zero content, such as fresh air. For measuring O₂, the instrument under similar conditions must indicate a value differing less than 0.1 % vol from zero within 60 seconds after changing from fresh air to an oxygen-free gas.

(4) The components in the exhaust gas, other than the components whose values are subject to the measurement, shall not affect the measurement results by more than the half of the modulus of the MPEs when those components are present in the following maximum volume fractions—

(a) 6 % vol CO;

(b) 16 % vol CO₂;

(c) 10 % vol O₂;

(d) 5 % vol H₂;

(e) O.3 % NO;

(f) 2 000 ppm vol HC (as n-hexane);

(g) water vapor up to saturation.

(5) An exhaust gas analyser shall have an adjustment facility that provides operations for zero-setting, gas calibration and internal adjustment. The adjustment facility for zero-setting and internal adjustment shall be automatic.

(6) For automatic or semi-automatic adjustment facilities, the instrument shall be unable to make a measurement as long as the adjustments have not been made.

(7) An exhaust gas analyser shall detect hydrocarbon residues in the gas handling system. It shall not be possible to carry out a measurement if the hydrocarbon residues, present before any measurement, exceeds 20 ppm vol.

(8) An exhaust gas analyser shall have a device for automatically recognising any malfunctioning of the sensor of the oxygen channel due to wear or a break in the connecting line.

(9) If the exhaust gas analyser is capable of operating with different fuels (such as petrol or liquefied gas), it shall be possible to select the suitable coefficients for the lambda calculation without ambiguity concerning the appropriate formula.