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[en] The uncertainty of dose measurements is obtained based on a number of factors that are inevitable. Therefore, the uncertainty must be determined carefully to ensure the reliability of dose measurements within a certain confidence level. The uncertainty of a secondary instrument NPL 2560 for X-ray dose measurements at this Secondary Standards Dosimetry Laboratory was 22%. This is the best uncertainty value that can be offered by this laboratory for calibration of radiation detecting instruments in Malaysia. (author)
[en] ''High flux'' diodes offer advantages over other dosimetric methods in X-ray beams of very high instantaneous intensity: linear accelerators and flash generators. They allow the measurement of pulsed doses and dose rates up to 1010r.s.-1, and give an immediate reading of the dose or peak dose rate by means of simple electronic devices
[fr]Les diodes ''haut flux'' remplacent avantageusement les autres procedes dosimetriques dans les faisceaux de rayons X a tres grande intensite instantanee: accelerateurs lineaires et generateurs flash. Elles permettent la mesure des doses par impulsion et des debits jusqu'a 1010r.s.-1. Elles permettent en outre une lecture immediate de la dose ou du debit crete a l'aide de dispositifs electroniques simples
[en] Ionization chambers, with air equivalent plastic walls, have been used as the main x-ray dosimetry system, since its response permits to give the doses in Roentgens. From the commercial availability of plastic scintillators with air equivalent atomic number we have studied its use in x-ray dosimetry. This paper devised a system with which it is possible to reduce side effects that introduce errors and obtain a response independent of energy, from 20 to 180 KeV and it is also expected to behave that way for higher energies. The system has a high efficiency and precision for a wide dose range and it is then a new alternative to measure x-ray doses. Results obtained with a prototype, built ad-hog, make it possible its use with dosimetric purposes with several advantages over conventional. (author)
[en] As the demand of a simple and precise method increases to evaluate the performance of the inverter type x-ray unit, we evaluated the usefulness of the recently-introduced X-ray Multi-Function Test Device (moldel : Xi (unfors)-prestige). We compared the performance of X-ray Multi-Function Test Device (XMFTD) which is non-inveasive type device with the performance of Dynalyzer III that has been most widely used inveasive type measure device. X-ray output dose was increased a little in the XMFTD, but both devices were below the performance evaluation standard, 0.002 in the output reproducibility. Linearity of XMFTD were below 0.1 which means that Dynalyzer III showed more excellency in linearity. As the the accuracy of exposure factor, 1.8 and 2 tube voltage, 2.01 and 2.3 tube current were measured. The exposure time was also measured by 0.01 sec ±10%. Both devices were within the acceptance of performance evaluation standard. We proved the usefulness of X-ray Multi-Function Test Device (model: Xi (unfors)-prestige) to evaluated the performance on reproductibility and linearity of X-ray output and accuracy of exposure factor of inverter type unit.