Calibraçäo e controle de qualidade em fotômetros e espectrofotômetros de diferentes procedências / Calibration and quality control in photometer and spectrophotometer from different origin

Os aparelhos espectrofotômetros devem ser controlados quanto à eficiência da lâmpada de emissäo, emissäo de energia espectral, cubetas, linearidade do receptor de fótons, energia parasita, entre outros fatores para que os erros inerente a esta metodologia sejam diminuídos. Neste trabalho com auxílio das provas de determinaçäo dos pontos isosbésticos para controle da emissäo de energia; linearidade do receptor de fótons; calibraçäo das cubetas e verificaçäo da energia parasita, avaliou-se 21 aparelhos espectrofotômetros de diferentes procedências

Effect of interposed skin at Doppler flow estimation at 5 and 10 MHz. With a description of a calibration device.

Flow measurements with high ultrasound frequencies (Doppler technique) can be used at quantitative estimations of flow. A calibrator for Doppler equipments is presented. The effect of skin as interposed material with 10 MHz and 5 MHz is discussed as are limitations in the apparatus itself especially when using 10 MHz ultrasound.

Aerodynamic size distribution of metered-dose bronchodilator aerosols.

The aerodynamic size distributions of 9 commonly used bronchodilator aerosols were determined by using a new instrument, the single-particle, aerodynamic relaxation time analyzer, which can measure the aerodynamic size of single particles and droplets in real time independent of density, shape, and other physical characteristics. The following commercial preparations were studied: Duo-Medihaler, Medihaler-Epi, Medihaler-Epi Medihaler-Iso, Norisodrine Aerotrol, Alupent, Metaprel, Isuprel Mistometer, Bronkometer, and Asthma-Meter. Count median diameters ranged from 0.62 to 0.82 micrometer, and mass median aerodynamic diameters ranged from 2.8 to 4.3 micrometer. The heterodisperse nature of the aerosols was demonstrated by the relatively large geometric standard deviations, which ranged from 1.5 to 2.1. None of these aerosols had a log-normal distribution; rather, the distribution curves were multimodal.