Certificate of calibration

Purchase and control measuring equipment and reference material necessary for internal calibration certification of calibrated instruments. Label them with the date when last calibrated and also date when the next calibration is due. Write a calibration report and, if necessary, an incident report or a calibration variance report. 

Mass of Cd, m g (SI unit)3 5 x 10-4 Certificate of calibration of balance giving period of validity of calibration and uncertainty... 

Temperature °C (SI unit)3 Used in the standard uncertainty of V Certificate of calibration of thermometer used to monitor laboratory temperature... 

Quantifying uncertainty components (from validation data, certificates of calibrations, manufacturer s information etc.) as standard deviations,... 

Balances are calibrated using a standard set of weights that come with a certificate of calibration giving their mass and uncertainty of this value, e.g. ... 

In cases where methods are similar or show common steps, it is essential to examine if no systematic bias is affecting the results. In some few cases, BCR was confronted with situations where participants had to use a common calibration material (certification of dioxins and furans in a fly ash extract). Such a situation offers the possibility of introducing a systematic error into the study and consequently of a bias of the certified value. Situations where suppliers cannot propose reliable calibration substances may oblige the certification body to provide a common material. It should remain an exception and if unavoidable, the producer of the common calibrant should follow a strict preparation procedure similar to the one described above for the certification of calibrants. 

A Certificate of Calibration for one particular radiometer is shown in Figure 30.18. For this radiometer, the output signal response is linear with the incident radiation level. This particular radiometer has a constant of 293.6 Btu/hr-fti per mV. So for example, suppose one aims this radiometer at a flame and the voltmeter reads 7.43 mV. Taking that number and multiplying it by the constant yields the radiation level 293.6 x 7.43 = 2181 Btu/hr-fti. 

The validation of control hardware and software basically requires the suitability of computer hardware assigned for the task, and that computer programs perform consistently within preestablished operational limits so that analysis of the effects of possible failures can be carried out. The calibration of instruments requires that the supplier of a freeze dryer provides a work certificate of calibration and that the user periodically verifies the performance of the instruments with an external authorized and certified instrument. In Refs. [26-33], useful information for GMP compliance, process, and computer system validation can be found. 

Determination of caustic production rate using a flow meter. This is the most convenient method, but it is not always favored because of the lack of certification of calibration. The accuracy of electromagnetic flow meters and Coriolis mass flow meters is very high (c. 0.5%) and reliable results have been obtained consistent with other methods of measurement. Both types can be used to integrate flow. The Coriolis type is particularly advantageous, as it does not require separate density determinations. 

Viscometers shall be mounted in the constant temperature bath in the same manner as when calibrated and stated on the certificate of calibration. See Specifications D446, see Operating Instructions in Annexes AI, A2, and A3. For those viscometers which have Tube L (see Specifications D 446) held vertical, vertical alignment shall be con-... 

Adjtist and maintain the viscometer bath at the required test temperature within the limits given in 6.3.1 taking account of the conditions given in Annex A2 and of the corrections supplied on the certificates of calibration for the thermometers. 

Al.2.1 Calibrate working standard viscometers against master viscometers having a certificate of calibration traceable to a national standard. Viscometers used for analysis shall be calibrated in comparison with working standard... 

A2.2.3.1 Unless otherwise listed on the certificate of calibration, the re-calibration of calibrated kinematic viscosity thermometers requires that the ice-point reading shall be taken within 60 min after being at test temperature for not less than 3 min. 

BCR Analytical Approach for the Certification of PAHs in Natural Matrix CRMs Prior to the certification analyses for the CRM, each participating laboratory has to prepare standard solutions of the analytes to be determined from certified reference compounds (purity >99.0 %) to calibrate their instruments for response and response linearity (multiple point calibration), detection limit, and reproducibility. In the case of PAH measurements, reference compounds of certified purity are used as internal standards, which are not present at a detectable concentration in the matrix to be analyzed (e.g. indeno[i,2,3-cd]fluoranthene (CRM 267), 5-methylchrysene (CRM 081R), benzo[f ]chry-sene (CRM 046), picene (CRM 168), and/or phenanthrene-dio). 

The revised database holds over 23 000 analyte values for 660 measurands and 1670 reference materials produced by 56 different producers, from 22 countries. The database is restricted to natural matrix materials (i.e. made from naturally occurring materials, excluding calibration standards manufactured from pure chemicals). Information has been extracted from the relevant certificates of analysis, information sheets, and other reports provided by the reference material producers. As a general rule, the authors have only included in the compilation reference materials for which a certificate of analysis or similar documentation is on file. Information included in the survey is on values for measurands determined in reference materials, producers, suppliers, the cost of the materials, the unit size supplied, and the recommended minimum weight of material for analysis, if available. The new searchable database has been designed to help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest and their samples to be analyzed see Table 8.3. 

As part of maintenance, some equipment may need to be calibrated. SOPs must include calibration methods, and a report format needs to be available at the time of calibration. Calibration SOPs must include pass/fail specifications as well as corrective actions to be taken in the event of calibration failure. For quality calibration standards use National Institute of Standards and Technology (NIST) traceable standards or other intrinsic standards of known purity, quality, and stability. These standards should have certificates attesting to their performance properties. After calibration, the metrologist or other responsible person should review the calibration reports to identify any issues with the equipment that may need further attention. 

Validations fall into two types prospective and retrospective. In prospective validation (see flow chart in Figure 2) the validation is done in a sequential manner, involving installation qualification and operational qualification (IQ/OQ) of equipment (e.g., chromatography instrumentation or column hardware). Appropriate calibrations accompany the IQ/OQ. Process qualification, or PQ, involves formal review and approval of a PQ protocol, execution of this protocol, and issuance of a formal PQ report which includes data analysis and recommendations (i.e., approval/certification of the process). If the process is not approved, the report may recommend a redesign or redoing of the validation protocol and, in some cases, a return of the process to process development for further optimization. 

For standard or proprietary polymer additive blends there is the need for analytical certification of the components. Blend technology has been developed for two- to six-component polymer additive blend systems, with certified analytical results [81]. Finally, there exist physical collections of reference additive samples, both public [82] and proprietary. The Dutch Food Inspection Service reference collection comprises 100 of the most important additives used in food contact plastics [83-85]. Reference compounds of a broad range of additives used in commercial plastics and rubber formulations are generally also available from the major additive manufacturers. These additive samples can be used as reference or calibration standards for chromatographic or spectroscopic analysis. DSM Plastics Reference Collection of Additives comprises over 1400 samples. 

Applications The application of the isotope dilution technique is especially useful in carrying out precise and accurate micro and trace analyses. The most accurate results in mass spectrometry are obtained if the isotope dilution technique is applied (RSDs better than 1 % in trace analysis). Therefore, application of IDMS is especially recommended for calibration of other analytical data, and for certification of standard reference materials. The technique also finds application in the field of isotope geology, and is used in the nuclear industry for quantitative isotope analysis. 

In addition to the requirements listed in clause 5.10.2 of ISO/IEC 17025, calibration certificates shall include conditions under which the cahbration was carried out, the uncertainty on the result and information about the measurement traceability, which is necessary for the interpretation of calibration results. 

The links to be established with all stakeholders should be clearly specified to enable the laboratory to function efficiently and meet the needs of its customers (the society through legislation and individuals). The laboratory is supplied with products (reagents, equipment, reference materials), receives services (accreditation, certification, provision of interlaboratory comparison schemes) and cooperates with other laboratories (cooperation in testing, provision of calibration services). 

Some viscosity tubes are calibrated at the factory, in which case a certif-cate of calibration, giving the calibration constant, is shipped with the tube. Such a constant can be checked in the laboratory using the method described above. Again, other measuring devices used in conjunction with this measurement must be properly calibrated. These include the temperature controller and the timer. 

Does the system include the retention of calibration certificates or data used in support of all calibration of measuring equipment Does the record system allow for calling forward, at the appropriate interval, equipment requiring calibration ... 

The standard recognizes (section 5.6.1) that the traceability requirements should apply to aspects of the method that have a significant influence on the result of the measurement. For an analytical chemistry laboratory, as well as for the reference materials used for calibrating the response of an instrument, balances will need to be calibrated from time to time, and appropriate certification of the traceability of glassware and thermometers must be available. 

Government agencies such as the U.S. Environmental Protection Agency set requirements for quality assurance for their own labs and for certification of other labs. Published standard methods specify precision, accuracy, numbers of blanks, replicates, and calibration checks. To monitor drinking water, regulations state how often and how many samples are to be taken. Documentation is necessary to demonstrate that all requirements have been met. Table 5-1 summarizes the quality assurance process. 

Certification of revalidation can be useful however, the manner in which formal approvals are documented is best left up to each individual firm, and use of formalized certifications should be considered entirely optional. Certification is documented testimony by qualified authorities that a system s qualification, calibration, validation, or revalidation has been performed properly and the results are acceptable. 

Lagarde, F., Asfari, Z., Leroy, M.J.F., Demesmay, C., Olle, M., Lamotte, A., Leperchec, R and Maier, E.A. (1999b) Preparation of pure calibrants (arsenobetaine and arseno-choline) for arsenic speciation studies and certification of an arsenobetaine solution (CRM 626). Fresenius f. Anal. Chem., 363, 12. 

BIPM (1999) Mutual recognition of national measurement standards and of calibration and measurement certificates issued by national metrology institutes, Bureau International des Poids et Mesures (BIPM), Pavilion de Breteuil, 92312 Sevres Cedex, France Internet www.bipm.fr... 

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