Verification of instruments is a procedure which includes examination and marking, and issuing of a verification certificate, that ascertains and confirms that the measuring instrument complies with the statutory metrological requirements.
Verification of instruments is legally regulated by the Law on Metrology ("OG of MNE", no. 79/08) and the bylaws.
Based on the Regulation on legal measuring instruments that are mandatory subjected to verification i.e. type approval of measuring instrument ("Official gazette of MNE", no. 81/09), legal measuring instruments are divided according to the field they are used in.
Type of measuring instruments to be subjected to type approval are listed in the Regulation, together with the method and the procedure of the type approval are defined in the Rulebook on more detailed procedure and method of examination and approving the type of a measuring instrument ("Official Gazette of MNE", No. 10/10). If the Regulation prescribes that approval is mandatory for a certain type of measuring instruments, the measuring instrument can't be verified unless the approval of the type is issued.
Verification of a measuring instrument can be initial, regular or extraordinary, and is carried out at the request. The Request Form for verification of a measuring instrument can be acquired in the Bureau of Metrology or on the Web page of the Bureau.
New measuring instruments shall be subjected to initial verification, as well as the measuring instruments that have not been verified before. The request for initial verification shall be submitted by a national manufacturer, importer, authorized distributor or natural person.
Regular verification of measuring instruments shall be performed periodically, within defined time intervals for certain measuring instruments (from one to twelve years). Owner of a measuring instrument or those using the measuring instrument shall submit it to regular verification. For regular verification of electric energy meters, water-meters, gas-meters, gas volume correctors, and heat meters, are responsible subjects that sell electrical energy, water, gas and heat energy.
Extraordinary verification shall be conducted after repair or refitting of measuring instrument or if it wasn't subjected to the regular verification within the defined deadline. The request for extraordinary verification shall be submitted by a person who has performed a repair or refitting of a measuring instrument.
Method of the verification is defined by the Rulebook on the method of determining the compliance with the metrological requirements for legal measuring instruments ("Official Gazette of MNE", No. 04/10).
For example, deadlines for regular verification of measuring instruments most commonly used are:
- taximeters, 1 year;
- devices for liquid fuels and liquefied petroleum gas, 1 year;
- non-automatic weighing instruments of range up to 9 000 kg, 2 years;
- automatic weighing instruments of range over 9 000 kg, 1 year;
- water-meters, 5 year;
- electricity meters for indirect connection, 5 years;
- electricity meters for direct connection, 12 years.
Deadlines for the regular verification of certain legal measuring instruments are stipulated by Rulebook on deadlines for the regular verification of the measuring instruments ("Official gazette of MNE", no. 86/09).
Verification of measuring instruments is performed by the Bureau of Metrology, or persons authorized for verification of measuring instruments. For now there are no persons authorized for verification of certain measuring instruments.
The Bureau of Metrology issues verification certificates, if the requester asks for it. The certificate is valid as long as the mark placed on the measuring instrument at the verification is.
Verification certificate expires if:
- period to which measuring instrument was verified has expired;
- fitting has been performed that can affect its metrological characteristics;
- measuring instrument is damaged so that it could lose any feature relevant to verification;
- mark has been destroyed, removed, changed or damaged in any other way;
- measuring instrument has lost its necessary metrological attributes although the mark it's been verified with isn't damaged;
- installation location of measuring instrument is changed.
In case of doubt in the correctness of legal measuring instrument, interested person may request from the Bureau of Metrology an extraordinary examination of the measuring instrument and issuing of examination report. The requester bears fees for extraordinary verification of measuring instrument that is if the verified measuring instrument meets prescribed metrological requirements. In the case that verified measuring instrument doesn't meet the prescribed metrological requirements, person who is responsible for the regular verification of the measuring instrument bears the fees. The method of the extraordinary verification of legal measuring instruments in use is defined in Rulebook on extraordinary examination of legal measuring instruments in use ("Official Gazette of MNE", No. 19/11), and is performed at the request. The request form for extraordinary examination of legal measuring instruments in use can be obtained in the Bureau of Metrology or at its web page.
Types, forms and method of placing marks that are used at the process of verification of measuring instruments, form and the content of the verification certificate and of the type approval certificate are prescribed in Rulebook on the types, forms and method of affixing marks that are used in the verification of instruments, as well as more detailed form and content of the certificate of the verification of measuring instrument and the certificate of the type approval of the measuring instrument ("Official gazette of MNE", No. 80/09);
Amount and the manner of fees payment in the field of metrology, amongst others for verification of measuring instruments, are prescribed in Decree on the amount and the manner of payment of fees in the field of metrology ("Official Gazette of MNE", No. 73/10).
In the metrology system of legal metrology in Montenegro, an important role is played by the persons authorized to prepare certain types of measuring instruments for verification. For now there are no persons authorized to perform tasks of national calibration laboratory and for verification of certain measuring instruments. Decision on authorization to prepare measuring instruments for verification is rendered by the Department of Economy, based on the expert opinion of the Bureau on the fulfillment of the prescribed requirements in terms of how the premises and staff are equipped.
If it's prescribed by the Rulebook on the requirements that have to be met, persons authorized to prepare measuring instruments for verification can, under the preparation, remove the national mark placed on the measuring instrument (except from devices for liquid fuels and liquefied petroleum gas and measuring systems for liquids other than water), in order to prepare the measuring instrument in terms of regularity and metrological characteristics. Verification i.e. placing the mark on a measuring instrument is performed only by an authorized employee of the Bureau of Metrology.