France Pavlovcic
There are many industrial and environmental media (furnaces, climatic chambers, industrial bathes, the weather etc.) where the quantities of the ambient, such as the temperature of fluids and the relative humidity of mixtures of gases, are measured for the purpose of control, when speaking of industrial media, and observations and analyses in many other cases. The measurements are carried out by sensors and instruments calibrated under stationary conditions. But, in industrial and environmental measuring, these sensors meet dynamic conditions of the measured quantity caused by both...
XVII IMEKO World Congress
· TC12
· 2003
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Robert Ambroziak, Marek Orzylowski
The article presents th e computer system to determine fusibility of ash obtained from solid mineral fuels, which is a vital parameter for proper exploitation of power and heating plants boilers. The system is based on analysis of the image of a heated ash sample. In the beginning, we describe the way in which the ash specimen is prepared, as well as its thermal processing, and also give criteria for specifying the characteristic temperature points of phase transitions according to the ISO 1171 standard. Later, we present the scheme of the apparatus for automated determination of ash...
XVII IMEKO World Congress
· TC12
· 2003
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Igor Pušnik, Jovan Bojkovski, Valentin Batagelj, Gaber Begeš, Domen Hudoklin, Janko Drnovšek
In the paper results of measuring the climatic conditions (temperature and relative humidity) in vehicles, which are exposed to the s un, will be presented. The measurements will be analysed with respect to the type of a vehicle, colour, availability of air-condition, and weather conditions.
XVII IMEKO World Congress
· TC12
· 2003
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Torbjörn Löfqvist, Kestutis Sokas, Jerker Delsing
This paper presents results from experiments using an ultrasonic gas flow meter measuring the speed of sound in air at varying air velocities, humidities and temperatures. The meter utilises the sing-around technique. The transducers in the meter are silicon-based ultrasonic transducers with a centre frequency of 800 kHz. In order to investigate the performance of the flow meter it was tested in a novel gas flow facility connected to a calibration facility for flow meters used for liquids. The Reynolds’ numbers for the investigated flow velocities ranged from 0 to 3,2·10 4 , the relative...
XVII IMEKO World Congress
· TC12
· 2003
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Stéphan Briaudeau, Bernard Rougié, Jeanne Marie Coutin, Georges Bonnier, Jean Bastie
A new temperature measurement process based on radiometric standard has been realised at BNM INM. A radiance-meter is used to calibrate a tunable monochrom atic source which is compared to a black body with a spectral spectroradiometer. The radiance m eter is calibrated against a cryogeni c radiometer. The spectral radiance measurement wavelength is selected by the spectroradiometer. The temperature is then deduced from the spectral radiance with the Planck's law. The monochrom atic source can be scanned over 10 nm around 830 nm in order to measure the slit function of the spectroradiometer....
XVII IMEKO World Congress
· TC12
· 2003
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Marjan Pohl, Zoran Kariž, Ivan Bajsic
This paper presents a facility for humid air generation – the humidity generator. The generator was developed for calibration of hygrometers. The principle of operation is based on the two-temperature method for humid air generation and the open circuit flow mode is applied. Saturation of the air is achieved by the water atomization in air flow. The generator is designed to operate in the test chamber temperature range from 5°C to 85°C and in dew point temperature range from 2°C to 35°C. The paper makes a point to the possibility the system works in nonsaturation mode and the comparison...
XVII IMEKO World Congress
· TC12
· 2003
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Sevilay Ugur, Humbat Nasibov
ITS-90 Radiation temperature Scale is defined only above the freezing point of silver. However, the need of calibration of radiation thermometers below this temperature is also important because many industries such as paper, cement, rubber makes use of the radiation thermometry for temperature measurements. Besides the temperature range of many radiation thermometers cover below and above freezing point of silver. This work will describe the radiometric calibration of a commercial thermometer at the fixed points.
XVII IMEKO World Congress
· TC12
· 2003
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Tohru Iuchi, Tohru Furukawa, Nobuharu Sato
This study aims to develop a practical radiation thermometry system of metals moving through in a high temperature furnace. In order to achieve this study, two problems; emissivity compensation of a target and elimination of background radiation noise filled in a furnace must be sorted out. We have successfully developed a method for simultaneous measurement of emissivity and temperature by use of polarized directional properties of the radiance from the target, in this case, stainless steel, and moreover a technique to eliminate background radiation noise using a pseudo blackbody installed...
XVII IMEKO World Congress
· TC12
· 2003
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Dariy Svet
The paper deals with the method of on line radiation measurement of the true temperature and emissivity in the process of heating or cooling. The method may be realized without any precalibration. The realization of the method is based on simultaneous measurement of the intensities of self-radiation and of directional reflected radiation on two wavelengths for three values of temperature. The method involves the use of relative directional reflectometry which does not require the validity of the Lambert law for radiating surface. For the method to be realized in practice, the accuracy of...
XVII IMEKO World Congress
· TC12
· 2003
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Achim Seifter, Konstantinos Boboridis, Andrew W. Obst
Laser polarimetry has been used for years to obtain normal spectral emissivity measurements on pulseheated materials. The method is based on the FRESNEL equations that describe reflection and refraction at an ideally smooth interface between two isotropic media. However, polarimetry is frequently used with surfaces that clearly deviate from this ideal condition. Questions arise with respect to the applicability of the simple FRESNEL equations to non-specularly reflecting surfaces. On the other hand, reflectometry utilizing integrating spheres provides a measurement of the hemispherical...
XVII IMEKO World Congress
· TC12
· 2003
· Download