In de afgelopen zes jaar is er veel aandacht besteed aan de ontwikkeling van meetstandaarden voor het siloxaangehalte in biomethaan en opgewaardeerde biogas. Biogas is wereldwijd van toenemend belang als energiedrager. Het vormt een milieuvriendelijk alternatief voor aardgas en draagt bij tot de vermindering …

The thermally-sensitive resistors (thermistors) used in VSL’s water calorimeter to detect the radiation-induced temperature change in water are affected by self-heat. The measurement current used to determine their resistance causes their temperature to increase above that of their environment. The self-heat …

Het onderzoek richt zich op het karakteriseren van een bepaald type multimeter, de AGILENT/HP3458A. Deze multimeter is tot op heden niet overtroffen in zijn nauwkeurigheid en kan onder andere wisselspanning (AC) en gelijkspanning (DC) meten. Het meten in het DC-bereik kan een factor 100 beter dan het …

When treating cancer by radiation therapy it is always the goal to irradiate the tumour as much as possible and to spare the healthy tissue around it. For this a new type of radiation therapy called Volumetric Modulated ARC Therapy (VMAT) has been developed. During VMAT treatment the radiation machine …

This report describes the work that has been done on the water calorimeter project at VSL. The calorimeter determines the absorbed-dose-to water Dw in gray, by measuring the radiation induced temperature change. The temperature of the water will change due to irradiation of a beam ionizing radiation. …

Research has been done to improve the understanding the self-heat effect, due to power dissipation, of temperature-dependant resistors in the VSL water calorimeter. A custom measurement program has been written to be able to control and read out three Agilent 3458A digital multimeters (DMMs). With these …

The treatment of tumours in cancer patients have become more advanced and thus more complex. The verification of the dose distribution, calculated by clinical physicists, have thus become more complicated. VSL has started the development on measurements of absolute dose distributions in an antrhopomorphic …