Internal calibration tests

The IQ is typically followed in close succession by the OQ protocol. The OQ confirms and documents that an instrument operates in accordance with the vendor s functional specifications. Again, similar to that for the IQ, the OQ protocol is often partly, if not totally, developed by the vendor of the instrument. In some laboratories, the internal calibration tests may be incorporated as part of the OQ protocol. In most cases the protocol is typically carried out by a vendor s qualified service engineer. Since the same service engineer often performs both the IQ and the OQ, the IQ and PQ are often combined as part of an overall IQ/OQ protocol. 

The RQ flex test kit (Merck) which uses specific test strips is useful for the semi-quantitative determination of several analytes. D(+) ascorbic acid can be determined in fortified food products with an accuracy of 85-115% (unpublished data), however the procedure cannot be applied to coloured food products. Added iron salts may be extracted from food products with dilute sulphuric acid and adjusted to pH2 with NaOH solution. Fe3+ is reduced to Fe2+ with ascorbic acid. Fe2+ reacts with Ferrospectral to form a red-violet complex. An internal calibration is provided on a barcode which is read by the RQ-flex reflectometer prior to any measurements. This avoids the need to calibrate the instrument with standard solutions. 

Internal standard test compound(s) (e.g., structurally similar analog, stable labeled compound) added to both calibration standards and samples at known and constant concentration to facilitate quantification of the target analyte(s). 

Use the protocols set out in the instrument manual for a pulsed NMR unit to perform the recommended self-tests and internal calibrations. 

The results of calibration tests must be properly documented in accordance with the requirements of the manufacturer and/or the applicable national or international standard for the instrument before it can be considered calibrated. 

The installed software package also contains the AMDIS libraries onsite.cls and onsite.isl for calibration, test, and internal standard compounds (see Section 2.2). After software installation the hard disks are assigned to a particular GC/MS system. Since each instrument (defined by serial number) may be combined with any of the 5 electronic modules, 12 GC modules and 10 injector modules in possession of OPCW the actual instrument configuration needs to be defined. This is achieved by installing configuration files for the... 

Fig. 40. The advantages of the DL-EPR are (1) only a 100 grit finish is necessary, as the anodic sweep cleans the surface, (2) intragrain pitting does not affect the ratio, and (3) no measurement of either surface area or grain size is necessary. The anodic sweep essentially gives an internal calibration for the method. Majidi and Streicher have shown excellent correlation between SL- and DL-EPR tests for Type 304 SS (32). DOS values measured by EPR have been included in models of intergranular SCC of sensitized stainless steel (34,35).

Reliable quantitative results are obtained by external calibration if automatic injectors or autosamplers are used. This method involves direct comparison of the peak responses obtained by separately chromatographing the test and reference standard solutions. If syringe injection, which is irrepro-ducible at the high pressures involved, must be used, better quantitative results are obtained by the internal calibration procedure where a known amount of a noninterfering compound, the internal standard, is added to the test and reference standard solutions, and the ratios of peak responses of the analyte and internal standard are compared. 

The distribution of elements around each femur was used as an internally calibrated measure of dynamic effects between bone and soil. The four analyses at each soil position were averaged, and the means for the various positions were compared to one another by the F-test 12, 13), which determines whether there is a significant difference among the means. A negative result indicates that all the means are statistically the same. A positive result indicates that at least one of the soil positions is distinct from the others. Thus, if the concentration of a given element decreases or increases with the distance from the bone (the result of leaching into or out of the bone), a positive result would be obtained. In addition, if the concentration above the bone is different from that below or on the side, a positive result also would be obtained. If only one soil point is anomalous, a positive result may be misleading. 

Wavelength accuracy tests conducted using appropriate external standards will prevent potential problems that could occur with proprietary internal calibration protocols. The exact nature of any calibration standard must be noted in a validation protocol. Rare earth oxides and glass standards are candidates for such calibration. 

In recent years, the drive towards international standards has led to a close examination of long-established test methods, and it has been found that the reproducibility ol many of the tests was poor. This in turn has not led to new tests but rather to the establishment of better standardization of test procedures. There has also been a growing realization of the need to calibrate test equipment with proper documentation of calibration procedures and results. 

All balances should be regularly calibrated and monitored for their performance. The applicable frequency of such tests should be based on risk assessment the higher the impact of deviations, the more often testing should take place. Calibration is to be performed by the user either manually (with an external calibration weight) or using the internal calibration. 

Hydraulic pressme test vent out all internal gases from the topmost point of the vessel fill the vessel completely with water. Blank all openings and provide calibrated test pressure gauge. Pressurise slowly to the specified test pressure and close inlet valves... 

For analyzers calibrated using internal calibration routine without blank correction, calculate the sulfur of the test specimen in parts per million (ppm) as follows ... 

Consider the addition of deuterated morphine (morphine-dj in which the hydrogen atoms of the methyl group are replaced by deuterium atoms. Figure 7.4) as the internal standard in the test portion of a sample. Most of the uncertainties described earlier will be counterbalanced by internal calibration. An imprecise dilution, a crack in the SPE cartridge, a loss of analytes by evaporation, an incorrect volume injected will all subject a sample to the same losses in standards and analytes. The chromatographic response of the analyte is systematically compared to that of the standard (see next section) so dosing will not be affected by all the uncertainties. 

This chamber has a sensitivity of 10 Amp per R /hr. The range of the gamma monitor is from 0.001 to 10 R/hr. The instrument is calibrated and tested by means of an internal calibration circuit, which is also used to set the trip level of the instrument. The normal trip level of the instrument is set in the range from 2 to 3 mR/hr. 

In the ideal case, all heat evolved in the measuring cell should be transferred to the surrounding heat sink. However, because this transfer is not perfect, the losses have to be corrected by calibration. Although electrical tests can easily be performed on a regular basis by an external located (relative to the flow vessel) resistance, there must also be internal calibration. In this case a... 

In this section results will be presented using test samples to determine the accuracy of our approach. Further on an example is shown using the system to analyse casting defects. For the experiments moderate projective magnifications between 1.1 and 1.4 were chosen. The test samples used to determine the accuracy of calibration, 3D defect position and volume estimation consist of several holes representing internal defects of different but known size and shape. 

The main purposes of the System of accreditation is to ensure reproducibility of measurements, harmonisation of rules and procedures of the National system of accreditation with guidelines of international organizations and national systems of different countries, creation of conditions for mutual recognition of the results of testing, calibration, attestation. 

Comparative evaluation of international and national requirements both in the part of the volume and frequence of calibration procedures and examination of devices for ultrasonic and radiographic testing was accomplished. This review showed that procedures specified in national documents on testing and documents of EAL coincide very much. 

ISO Guide 25 (1990) Guidelines for assessing the competence of calibration and testing laboratories. International Organization for Standardization, Geneva. 

The procedure employed for the establishment of the chemical reference substances used in these assays has been previously published (Sandrin et al. 1997). The CRSs for the microbiological assays of antibiotics are first submitted to the chemical tests of the monograph. If the results are satisfactory, a collaborative microbiological assay is carried out, using the International Standard as calibrator. Thus, these reference substances are considered to be secondary reference substances since they are calibrated against existing standards. Potency is expressed in International Units. If an International Standard does not exist, European Pharmacopoeia Units are used. 

ISO (1990) ISO/IEC 25 General requirements for the competence of calibration and testing laboratories and ISO/IEC DIS 17025 General requirements for the competence of testing and calibration laboratories. International Standards Organization, Geneva. 

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