Legal Metrology Research Articles

FEATURES OF TESTING OF THE BUILT-IN SOFTWARE OF MEASURING INSTRUMENTS

Protection against unauthorized modification or its components, measurement data and protection against external unintentional and accidental interference are particularly important for measuring instruments (MIs) software. The possibilities of ensuring the security of built-in MI software, as well as MI as a whole, are considered. The analysis of the main features of built-in MI software on the basis of documents, guidelines and recommendations of international and regional organizations in the field of legal metrology are shown. The characteristics of MI software in accordance with international and regional documents, guidelines and recommendations are the establishment and regulation of such tests, which must be provided in the testing methods for specific MI with embedded software.

INTERNET OF THINGS OF ELECTRONIC SEAL BASE ON GPRS SHORT MESSAGE SERVICE AND THINGSPEAK

The field of metrology is mainly legal metrology; seals are closely related to the guarantee or validity of a measuring instrument. Seals are designed so that it is not easy for other parties to open the seal. Seal damage must be identified as soon as possible. The application of the Internet of Things (IoT) is needed in the process of sending data in real-time. IoT technology can be applied to electronic seals to know and record the condition of the measuring device. Broken seals caused by irresponsible parties can cause losses to consumers and owners of measuring instruments. Electronic seals are expected to be able to detect seal damage caused by abuse of authority or fraud. The broken seal will send data to the server as well as SMS (Short Message Service) to the related party. Electronic seals can send damage data via SMS within 20 seconds with a success rate of 92% and sending data through the ThingSpeak web server within 40 seconds with a success rate of 82%.

On the effect of the mounting angle on single-path transit-time ultrasonic flow measurement of flare gas: a numerical analysis

The oil and gas industry needs accurate flow measurement since it is required by law, and so, considered as a field of legal metrology. Nevertheless, curves and other commonly found obstacles may affect the quality of flow measurements, due to disturbances to the flow, such as swirl and asymmetries in the velocity profile. Single-path ultrasonic flow meters are often used to measure the flow rate in flare gas installations, even though they are sensitive to such disturbances. The present paper uses numerical tools to obtain disturbed flow fields downstream from single- and double-elbow pipe installations, aiming to investigate the effects of the mounting angle on disturbed ultrasonic flow measurements, taking into consideration the contributions of all velocity components. Several transducer mounting angles from 0° to 180° are assessed varying the Reynolds numbers (based on the pipe diameter D) from $$10^{4}$$ to $$2 \times 10^{6}$$ and axial positions up to 80D downstream from the curve. Results indicate that the correction factors for installation effects are mostly greater than in the guidelines and regulations, which suggests that, in real situations, the flow rate is being underestimated. Moreover, badly located measuring installations may be upgraded just by changing the mounting angle of the ultrasonic transducers.

Preface

The IV International Scientific and Technical Conference “Metrology on Physicochemical Measurements” was held 17-19 September 2019 in Suzdal, Russia. It was organized by the All-Russian Scientific Research Institute of Physicotechnical and Radio Engineering Measurements (VNIIFTRI) with participation of the Cooperation on International Traceability in Analytical Chemistry (CITAC) under the slogan “Let’s speak about measurement uncertainty”.About 100 participants from metrological, academic and high-education institutes, metrology service centers and other organizations of Belarus, Bulgaria, China, Israel, Germany, Switzerland and Russia took part in the Conference. There were 44 oral presentations, some posters and a small exhibition.The Conference program included scientific and technical topics from the fields of electrochemistry, spectrometry, chromatography and other instrumental methods of physicochemical analysis; reference materials; measurements of dispersed parameters of particles in heterogeneous media, including aerosols and suspensions and air ions; applied and legal metrology and others.During the framework of the Conference, interesting suggestions were made to further improve the level and quality of the metrological work performed, current problems in the field of ensuring the uniformity of measurements were highlighted, the opportunity to exchange experiences, establish contacts between organizations was provided. New achievements in the field of fundamental and applied research in the field of metrological support of physico-chemical measurements, world and domestic achievements in the development of measuring equipment in this field are presented.After welcoming remarks by Prof.Dr.Sergey Donchenko, General Director of VNIIFTRI (Russia), such well-known scientists as Prof.Dr.Alfred Wiedensohler, Head of Experimental Aerosol and Cloud Microphysics Department (Leibniz Institute for Tropospheric Research, Germany); Dr. Samuel Wunderli, CEO “atomolmetron” GmbH, Independent Consultant on Metrology, CITAC member (Switzerland); Dr. Ilya Kuselman, Independent Consultant on Metrology, Editor of CITAC News and Chair of the IUPAC Interdivisional Working Party for Harmonization of Metrology and Quality Guidelines (Israel); Dr. Anatoly Trubitsyn, Scientific Advisor of Gorniy TsOT Ltd. (Russia); Dr. Natalia Muravskaya, Head of QM, VNIIOFI, Chair of COOMET TC 3.1”Quality Forum” (Russia); Dr. Anastasia Semenova, Deputy director of the Institute of Food Systems after Gorbatov (Russia) and e.g., as well as many young scientists took part in the conference with reports. In total, more than 40 reports were presented at the conference, of which 16 reports were made by scientists of VNIIFTRI. The conference was very active, heated discussions continued during the breaks.The participants were satisfied by the scientific level and usefulness of the Conference.The next such conference is planned by VNIIFTRI for 14-16 September 2021 in beautiful historical place - Park-Hotel “MOROZOVKA”, Moscow region, Mendeleevo, Russia.The Scientific secretary of the ConferenceDr. Narine G Oganyan

Testing normality

Abstract In metrology, the normal distribution is often taken for granted, e. g. when evaluating the result of a measurement and its uncertainty, or when establishing the equivalence of measurements in key or supplementary comparisons. The correctness of this inference and subsequent conclusions is dependent on the normality assumption, such that a validation of this assumption is essential. Hypothesis testing is the formal statistical framework to do so, and this introduction will describe how statistical tests detect violations of a distributional assumption. In the metrological context we will advise on how to select such a hypothesis test, how to set it up, how to perform it and which conclusion(s) can be drawn. In addition, we calculate the number of measurements needed to decide whether a process departs from a normal distribution and quantify how sure one is about this decision then. These aspects are illustrated for the powerful Shapiro-Wilk test and by an example in legal metrology. For this application we recommend to perform 330 measurements. Briefly we also touch upon the issues of multiple testing and rounded measurements.

Measuring the oscillometric method contribution to the measurement uncertainty of automated sphygmomanometers using a patient simulator

The sphygmomanometer is a widely used device for non-invasive blood pressure measurement. Systematic measurement errors and uncertainties can affect measurements, consequently, impacting diagnosis or medication. In order to maintain the conformity of the instruments, sphygmomanometers are usually under control of legal metrology demanding periodical verifications. Automated sphygmomanometers are based on the oscillometric method, measuring small changes of arterial blood pressure occurring in the cuff. Once pressure working standards are unable to generate the oscillometric pulses, verifications are performed on the sphygmomanometer on its manometer mode, disregarding the contribution of the oscillometric mode to the uncertainties. The present study investigates the contribution of the oscillometric method to the expanded measurement uncertainty. We used a patient simulator in four sphygmomanometers available in the market for consumers. The results show that the contribution of the oscillometric mode to the expanded uncertainty can be significant, varying from 0.16 to 1.56 mmHg and from 0.12 to 1.55 mmHg, for 100 and 150 mmHg, respectively. We also observed different contributions to the uncertainty for systolic and diastolic blood pressure.

Certified Reference Materials and Metrological Traceability for Mycotoxin Analysis

Abstract In the past decade, with the signing of the joint declaration by the International Bureau of Weights and Measures (BIPM), the International Organisation of Legal Metrology, the International Laboratory Accreditation Cooperation, and the International Organization for Standardization, and the issuing of new international standards such as ISO/IEC 17025 and ISO 13528, metrological traceability has become more and more important for the mutual recognition of measurement results. It is found that the important factors for ensuring the accuracy of results are not only relevant to calibrants but also to the analysis procedure. This paper focuses on the analysis of key factors that affect measurement results, such as analytical methods, reference materials (RMs), and proficiency testing of mycotoxins. The Capacity Building and Knowledge Transfer Programme for mycotoxins, led by the BIPM, which aims to establish a global measurement system traced to the Système International d’Unités (SI), is well illustrated. Furthermore, this paper suggests to stakeholders that great effort is needed to promote the effective use of certified RM resources that are traced to the SI and globally recognized by the International Committee for Weights and Measures to finally realize “one measurement, global recognition.”

Penegakan Hukum terhadap Tindak Pidana di Bidang Pengukuran

In trade traffic and buying and selling transactions, measuring instruments, measurements, and scales are one of the most vital and necessary facilities in supporting the realization of a transaction of goods and services. Its purpose is to determine the unit and weight of the goods and services which are the object of the trade and the transaction. For that reason, in every trade transaction, especially trade in goods, measurement tools, measurements and scales that meet legal metrology standards are needed. or legal metrology or legale metrology. This means that the measurement tools, measurements, and scales used in each transaction must have the legality and validity of the agency that is authorized to do so, namely from the Legal Metrology or Metrology Technical Implementation Unit (UPT) which carries out the metrological tasks residing in Provincial and Regency / City level. This research is an empirical study conducted in the city of Palu using the interview and questionnaire method. The results showed that there were still many violations committed by Legal Metrology starting from the need to guarantee fairness in trade, especially in the area of measurement and weighing. Legal metrology is mainly concerned with measurement tools regulated by law. Irregularities in legal metrology among traders often occur due to lack of legal awareness and ignorance of the laws governing legal metrology. Factors inhibiting law enforcement against legal metrology criminal acts include a lack of public awareness about the law itself and a lack of socialization about threats criminal offenses against legal metrology abuse.

Field verification of thermal energy meters through ultrasonic clamp-on master meters

The measurement of heat consumption in buildings through thermal energy meters presents numerous metrological issues due, for example, to the installation and operational conditions (e.g. presence of plant constraints, low flow rates, low temperature differences between flow and return) leading often to unacceptable measurement errors and uncertainties. Therefore, in several EU countries, to guarantee consumer protection it is mandatory to carry out periodic inspection both in the laboratory and in the field to assess their accuracy, while in service. In this work, the authors present the results of experimental campaigns aimed at analysing the key metrological concerns for clamp-on master meters during in-field verification of thermal energy meters. The results showed that particular care should be paid to the meter configuration and installation of the transducer and that legal metrology statutes in terms of permissible error and uncertainty for fielded meters are often very difficult to comply with.

Implementasi Rancangan Pelatihan Kemetrologian bagi Juru Timbang Menggunakan Metode ADDIE

Legal metrology is a very large and complex field to be implemented. In realizing orderly measurement for all of Indonesia, very large human resources are needed. A total of 1900 Metrology Human Resources currently available cannot meet the needs of the community, which includes at least 14.230 traditional markets and hundreds of modern markets spread throughout Indonesia. Adding large numbers of Metrologi personnel from ASN is very difficult, the most likely choice is to recruit personnel outside metrology such as market managers of traditional and modern market. This situation encouraging idea to recruit weighers whose task is to check the scales in traditional and modern markets. Through the ADDIE method which include analize, design, develop, implementation and evaluation a training model for weighers is designed. As a result, two days of training (20 JP) with classroom learning methods and laboratory practices is held . Furthermore, the weigher conducts trials in the market where each of them is on duty. The evaluation results with an average value of 4.43 of 5 Likert Scale indicate that the training is satisfying and meets the needs of the knowledge and skills of the weighers before duty.
 

Improvement of the Russian National Secondary Standard of the Unit of Length Using Latest Ultra-Stable Laser Equipment

Introduction. Increasing demands of precise geometry measurements by science and industry cause the necessity of improvement in an associated branch of legal and practical metrology. One of the most significant fields is the measurement of internal dimensions and so the issues with the unit of meter transfer. Now we face the situation when the current accuracies of National standards of different levels in corresponding traceability chain (reference rings measurements) get close to each other. This means that we have to make the standard of upper level more precise. One of the obvious ways is to apply the latest ultra-stable laser locked to a frequency comb.Objective. The objective is to propose possibilities for improvement of the National secondary standard of the unit of length by researching its measuring capabilities to minimize measurement uncertainty.Materials and methods. The calculation of expanded uncertainty of internal diameter measurements by the National secondary standard of the unit of length is performed according to the international document «Guide to the Expression of Uncertainty in Measurement» JCGM 100:2008 approved by BIPM. The secondary standard research results represented in previous reports and publications are also taken into consideration.Results. Detailed uncertainty budget for the proposed measuring system is given as well as graphical data representing the accuracy improvement.Conclusion. Actions for minimization of measurement uncertainty components of the National secondary standard of the unit of length in the field of reference ring internal diameter measurements in combination with state-of-the-art laser interferometer system improve it to the next frontiers of accuracy and precision.

Malaysians’ awareness towards legal metrology and Weights and measures act, 1972

Purpose The purpose of this study is to examine the level of awareness of the public about Weights and Measures Act, the awareness of Metrology Corporation Malaysia (MCM) services such as verification sticker and the awareness about ways to file a complaint by the public.Design/methodology/approach A quantitative research methodology survey was used to collect data. The quantitative collected data were analysed to achieve the objectives of this study.Findings The results of this study showed a low awareness level of the general public, especially non-stakeholders, knowledge, attitude and actual behaviour about the work of verification and re-verification and checking for verification sticker as well as ways of complaining if the instrument is not verified. In addition, the number of stakeholders working in the legal metrology area was high and Facebook was one of the most preferred media by the public to get awareness messages.Research limitations/implications It is recommended for other researchers to enlarge the sample size and implement the study on more companies in the industry.Practical implications The findings of this study revealed that public awareness, knowledge and intention have significant and positive relationship with actual behaviour of the public and that awareness, knowledge and actual behaviour among the non-stakeholder were low compared to the stakeholder. The results also enriched the stakeholders in legal metrology for improving public awareness, knowledge and actual behaviour toward the legal metrology and Wight and Measure Act, 1972.Social implications This study shows that Facebook was one of the most preferred media by the public to get awareness messages. This reflects the important role that social media plays. This is useful to the companies because it helps them understand the preferences of public in the society. In addition, the results of this study are useful to the decision-makers in the industry, which is expected to impact the performance of such companies.Originality/value This study is among the few studies conducted in the Malaysian context.

The Design and Application of Legal Metrological Verification Institution Management System Based on B/S Architecture

As the statutory metrological verification institutions authorized by the Inner Mongolia autonomous region bureau of quality and technical supervision, in order to better development and improvement of their management level and ability, Inner Mongolia electric power science & research institute electricity measurement test center not only meet the requirements of JJF1069,but also adopted the international general laboratory management standards: ISO/IEC17025 to establish management system and standardize management. Due to the relative lag of management methods and processes and the low degree of management informatization, the management cost is constantly increasing and the management difficulty is constantly increasing. Therefore, the central laboratory must improve and optimize the management process according to the actual situation of its own development, establish an efficient management system, and make full use of the information means to achieve fine management. This paper designs the management system of the legal metrological verification institution from two aspects of the overall structure and system demand analysis

Quality assessment of measurement instrument software with analytic hierarchy process

A comparative analysis of the results of conformity assessment of software for measuring instruments (MI) was carried out. For comparative evaluation, eight MI software with built-in and universal computers were selected. Selected MI software was preliminarily evaluated by methods and algorithms that are based on the requirements of national standards and documents of international and regional legal metrology organizations OIML and WELMEC. Based on the results of the analysis of the requirements of the WELMEC guidelines for testing MI software, generalized and particular indicators were selected for assessing the quality of MI software. Expressions to obtain the numerical value of each partial indicator for each generalized indicator was generated.For comparative evaluation, the analytic hierarchy process (AHP) was chosen, since it allows comparing and quantifying alternative solutions. For the purpose of relevant comparison, when evaluating a specific MI software, all compared elements were taken into account. The latter were grouped into generalized indicators, each of which was evaluated separately. Pairwise comparisons and all other stages of assessment using AHP were carried out on the basis of generalized indicators. For pairwise comparison of all quantitative and qualitative indicators with the presentation of the equation in a quantitative form, the Saati scale was used. The weight coefficients of each partial indicator were determined by the expert method.The main indicators for MI software with a built-in and universal computer were determined, which have the greatest impact on the results of conformity assessment. It was found that without the presentation of documentation and identification of MI software with built-in and universal computers, it is impossible to begin the conformity assessment procedure in accordance with the requirements. The test indicator of storage devices and the special test indicator of software for particular MI are some of the significant indicators. At the same time, the reading test indicator and the test indicator of software separation levels are practically not applicable and can be neglected.

PENERAPAN SANKSI PIDANA PADA PUTUSAN NO. 870/PID.B/2016/PN.JKT.SEL. DITINJAU DARI UNDANG-UNDANG NO. 8 TAHUN 1999 TENTANG PERLINDUNGAN KONSUMEN DAN UNDANG-UNDANG NO. 2 TAHUN 1981 TENTANG METROLOGI LEGAL (STUDI KASUS PUTUSAN NO. 870/PID.B/2016/PN.JKT.SEL.)

Gasoline or fuel oil is a necessity for society, especially for motor vehicle owners. In Indonesia, Pertamina as one of the fuel suppliers cooperates with the private sector to offset business competition with gas stations from abroad. In terms of Pertamina gas stations that are partnering with the private sector, cheating is not uncommon, such as the dosage of fuel oil that is not in accordance with the truth. As happened at Pertamina gas station in Rempoa area where the perpetrators involved 3 gas station managers and 2 gas station employees using additional equipment installed in the fuel dispenser and controlled using a remote control. With the existence of criminal sanctions in both laws, Act No. 8 of 1999 concerning Consumer Protection and Act No. 2 of 1981 concerning Legal Metrology, so that the actions of these perpetrators can be criminally accountable as can be seen in the Decision of the South Jakarta District Court Number 870/Pid.B/2016/PN.JKT.SEL. How is the application of criminal sanctions on Decision No. 870/ Pid.B/2016/PN.JKT.SEL. reviewed from Act No. 8 of 1999 concerning Consumer Protection and Act No. 2 of 1981 concerning Legal Metrology? The author use normative legal research and uses interview data as supporting data. The results of the study revealed that the criminal sanctions imposed on the three gas station managers were considered appropriate even though the maximum sentence was not applied, but the judges had their own freedom and legal considerations in deciding cases.

VNIIMS standard base of in the field of measuring the amount and properties of substance – measurements in chemistry and biology

The issue of the role of VNIIMS as the leading scientific organization in the field of legal metrology and the leading scientific and practical centre for metrological support of various sectors of the national economy is considered. The paper provides information on the equipment of the institute with standards in the field of physical and chemical measurements. The characteristics of experimental sample of the State Primary Standard of the unit of catalytic activity – katal, characteristics and fields of application of state standards of units of the VNIIMS in the field of physical and chemical measurements are given. The describes the plans of VNNIMS in accordance with the List of Critical Technologies of the Russian Federation, state programs for the development of industries.

THE MINERAL WATER TESTS METHODS METROLOGICAL ANALYSIS AND THE PROPOSALS ON THEIR IMPLEMENTATION IN UKRAINE

In connection with the necessity to unify the procedures and requirements applicable to goods and services, first of all, with regard to conformity assessment, in order to eliminate technical barriers to trade, a list of methods for testing mineral waters has been analyzed, according to which their assessment of conformity and determination of individual safety and quality indicators. The paper analyzes the metrological characteristics of the methods approved in the form of international, national standards, standards adopted before 1992, test methods for assessing their suitability for implementation not only in the testing, but also in the production laboratories. According to the results of the analysis of 42 indicators of the measurement methodology, which are specified in DSTU 878-93 (regulatory document on packaged mineral water) and GSTU 42.10-02-96 (normative document on medical waters used in sanatorium practice), 13 indicators , which are mandatory, as they are specified in the relevant normative documents, are not valid. According to the results of the analysis of the metrological characteristics of the methods of testing the indicators of safety and quality of mineral waters, a list of methods of tests of mineral waters for the period 2019-2021 has been developed, which includes national standards certified in Ukraine methodology and GOST for drinking water, in particular, on sulfates, ammonium and iron . However, the effect of these GOST on the testing of drinking water after 2021 will be abolished, and they should also be replaced either internationally or to develop national standards. In selecting the methods of testing mineral waters, two aspects were taken into account: the conformity of metrological characteristics of the methods during the assessment of the conformity of mineral waters, taking into account the features of the composition of the mineral water itself (applicability of the method for both low and high mineral waters), and the economic feasibility of testing for the appropriate method (due to the impossibility of many testing and production laboratories to use high-value equipment). In order to provide modern standards (international and national) of packaged mineral water producers and test laboratories conducting an assessment of the conformity of mineral waters, a list of methods for testing mineral waters, which is to be developed in Ukraine for the replacement of interstate GOST or methods, the metrological characteristics of which do not correspond to the current one, is proposed. in Ukraine the rules of legal metrology, and to give them the status of national standards (for the definition of Pseudomonas spit, sulfates, ammonium, bro copper and iodide). This will enable Ukrainian producers of packaged mineral water to optimize production costs for the production of Ukrainian products and successfully expand its share in the foreign market.

Certified Reference Materials and Metrological Traceability for Mycotoxin Analysis.

In the past decade, with the signing of the joint declaration by the International Bureau of Weights and Measures (BIPM), the International Organisation of Legal Metrology, the International Laboratory Accreditation Cooperation, and the International Organization for Standardization, and the issuing of new international standards such as ISO/IEC 17025 and ISO 13528, metrological traceability has become more and more important for the mutual recognition of measurement results. It is found that the important factors for ensuring the accuracy of results are not only relevant to calibrants but also to the analysis procedure. This paper focuses on the analysis of key factors that affect measurement results, such as analytical methods, reference materials (RMs), and proficiency testing of mycotoxins. The Capacity Building and Knowledge Transfer Programme for mycotoxins, led by the BIPM, which aims to establish a global measurement system traced to the Système International d'Unités (SI), is well illustrated. Furthermore, this paper suggests to stakeholders that great effort is needed to promote the effective use of certified RM resources that are traced to the SI and globally recognized by the International Committee for Weights and Measures to finally realize "one measurement, global recognition."

A Method for Remote Estimation of Wattmeter’s Adjustment Gain

A method for remote wattmeter (RW) adjustment is introduced in this paper. The estimated adjustment gain is intended for corrections of wattmeter's indications. Currently, legal metrology regulations do not allow such type of adjustment of certified instruments in the field. However, the proposed adjustment could be applicable in the areas of private or industrial subaccounting, home automation, and so on. If the achievable uncertainty could be specified, the method might be suggested for the wattmeter's calibration or verification. The implementation of remote adjustment becomes possible if both remote and reference wattmeters are connected to the same electrical grid and are equipped with a data communication channel. The main idea of the method is based on a temporary injection of the additional load at the location of remote device and acquisition of synchronized power readings by both reference and remote devices. The acquired readings are then processed to derive an adjustment gain of the RW. The proposed method aims to cancel an influence of the measurement unit propagating medium between the reference and remote devices. It is assumed that the characteristics of the medium are constant during the short period that is necessary to acquire readings. It is demonstrated that using the simulation of the proposed setup in the case of typical power losses in distribution lines, the adjustment gain can be estimated precisely. It is shown that in the case of remote measurement, the injected load power uncertainty can be reduced by averaging the acquired power samples.

Uncertainty study of fiscal orifice meter used in a gas Algerian field

Uncertainty variation of a fiscal orifice measurement system used in an Algerian natural gas exportation station is studied using data from a natural gas production field known as Gas Tin Fouye Tabankort (GTFT) located in the south-east of Algeria. The expected results are uncertainty calculus over a range of temperature and pressure variation and to the customs authorities’ allocation.In fact, each quantity of measured fluid flow has certain uncertainty and then the fiscal measurement station is very important for gas exportation, which means the income. Therefore, the pursuit of flow metering device uncertainty and its influence on the measured quantities in the transmission networks is very important.For that, the uncertainty caused by flowmeter in the measurement station causing economical revenue fluctuations is studied. The work was done to justify why there is a production decrease of hydrocarbons without identifying reasons during summer. The difference between the mass flow rate quantity produced and the transmitted value was important that is why our work is done to clarify exactly from where the problem can come.The measurements setting with two operating conditions (gas temperature and pressure) show that the uncertainty is dominated by seasonal temperatures and pressures variations which induce fluctuation in gas and pipe temperatures and influence the metrological performance of the transmitters. Indeed, the metrological measurement chain performance is affected also by these two operating conditions.The present work is done according to the ONML (National Legal Metrological Office) instructions regarding differences between the measured and the seller values represented by the mass flow rate.In natural gas transmission network, the important problem in the management and control of the network is represented by the unaccounted for gas, a quantity of measuring error which is to be considered in the equation of network balancing. One of the unaccounted for gas sources are the environmental conditions and systematic measurement errors.In this work, the calculation of the combined uncertainty of the mass flow rate measured by an Orifice fiscal gas metering plant is done. From the results founded, the authors confirm that the uncertainty in the measurement system causing by the climatic conditions generates unaccounted for gas.