Tag Archives: measurement

745–750 P. Kic
Influence of air-conditioning on dust level in drivers’ cabin during the harvest of grain
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Influence of air-conditioning on dust level in drivers’ cabin during the harvest of grain

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
Correspondence: kic@tf.czu.cz

Abstract:

The period of grain harvest is characterized by dry and hot summer weather. During the grain harvest is generated large amount of dust which significantly influences surroundings, but mainly drivers are exposed to dust pollution. The aim of this paper is to present results of microclimatic research focused on dust pollution in drivers’ cabin of tractors and combine harvesters of different construction used for harvest of grain. The machinery selected for this research includes the old but also very modern tractors and combine harvesters which are equipped with air conditioning. In the frame of this research the concentration of air dust was measured by exact instrument DustTRAK II Model 8530 aerosol monitor. Using the special impactors the PM1, PM2.5, PM4, PM10 size fractions were also measured. Obtained results of measurements were evaluated and concentrations of different size of dust particles were analysed. Results of different indoor conditions measured in new and old machinery are generalized.

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700–706 J. Hart, and V. Hartová
The next generation of multiple temperature sensor
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The next generation of multiple temperature sensor

J. Hart¹,* and V. Hartová²

¹ Czech University of Life Sciences Prague (CULS), Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
² Czech University of Life Sciences Prague (CULS), Faculty of Engineering, Department of Vehicles and Ground Transport, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: janhart77@gmail.com

Abstract:

Long-term and short-term measurements of temperature at different depths in soil have always been very complicated. The solution that was used until now was measuring using soil thermometers. Measurements were done at shallow depths and generally only allowed for measuring of one temperature, and always at the one depth which was determined for the measurement (normally 5, 10, 20, 50, 100, 150 and 300 cm). These problems were relatively limiting and impractical. It was therefore necessary to devise an alternative for a simple and effective solution that would eliminate these disadvantages – it was necessary for a probe to allow temperature to be measured at different depths at one measuring point without having to change its position. A requirement simultaneously arose for the need to be able to measure temperatures at greater depths, and a multiple probe was therefore conceived consisting of a rod for dynamic penetration tests.

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1119–1126 P. Neuberger and P. Kic
The use of unsteady method for determination of thermal conductivity of porous construction materials in real conditions
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The use of unsteady method for determination of thermal conductivity of porous construction materials in real conditions

P. Neuberger¹* and P. Kic²

¹ Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamýcká 129, CZ165 21 Prague, Czech Republic
² Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: neuberger@tf.czu.cz

Abstract:

The possibility to determine the thermal conductivity of construction materials outside the laboratory conditions is useful for professional practice mainly for control and inspection activities on real existing buildings. The requirement to determine the thermal conductivity can be useful above all for different thermal insulation materials but for other materials as well, even for compact soils or rocks. This paper describes methods and instrument which can be used for these measurements, as well as the results of measurement of porous building materials. Measurements presented in this paper were carried out by the needle and surface sensor. Four different materials were selected for verification of technical parameters of Isomet 2104. Besides the thermal conductivity there were determined also thermal diffusivity and volume-specific heat capacity of materials. The carried out measurements confirmed the applicability of this device for practical measurements of thermal conductivity in real conditions. For porous materials, there were determined significant differences between the data presented by the manufacturer or in the literature and measured values, in some cases. Differences between the measured values of thermal diffusivity and volume-specific heat capacity of porous materials were always statistically significant. Authors tested different materials including thermal insulation based on agricultural products.

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768–778 M. Hromasová and M. Linda
Analysis of rapid temperature changes
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Analysis of rapid temperature changes

M. Hromasová* and M. Linda

Czech University of Life Sciences in Prague, Faculty of Engineering, Department of Electrical Engineering and Automation, Kamycka 129, CZ165 21 Praha – Suchdol, Czech Republic
*Correspondence: hromasova@tf.czu.cz

Abstract:

 The analysis of rapid temperature changes in the dynamic system is described in the paper. Temperature changes are in range of tens of milliseconds. The sensor we used has a significant influence on the dynamic system. In these cases we need to use thermocouples that have appropriate transfer characteristics and can be manufactured with a low time constant. The time constant directly corresponds with weight and size of the sensor. The quality factor is usually in a range between 0.98 and 0.995. Information about the temperature course is particularly important in the field of dynamic systems, e.g. agricultural machines where the switching components are overloaded by pulse switching of technology systems. For the object analysis we use the thermocouples with diameter 0.012 mm with non-encapsulated finish and 0.12 mm with suppression of interference impact and comparative temperature fluctuation. For the analysis of dynamic temperature changes we conduct a measurement with a load factor change, which is the mean value of power change, expressed as ratio of the pulse duration to the delay between pulses, this way we will affect the measurement conditions. As a solution we use measurement methods for a steady state, an impulse test and a method of local measurement of temperature. Compared to a real principle of a component we do not increase temperature of the environment during experiments. The results of measurement can be applied for design and implementation of switching systems for electronic circuits with signal modulation and power load.

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245-252 J. Papez and P. Kic
Heating and ventilation in milking parlours
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Heating and ventilation in milking parlours

J. Papez* and P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, 16521 Prague 6, Czech Republic; *Correspondence: papez@tf.czu.cz

Abstract:

The aim of this paper is to show the results of the measurement of main microclimatic parameters (temperature and relative humidity) in milking parlours and compare the obtained results with values recommended in relevant standards. Temperature and relative humidity can affect animal welfare as well as the well-being of workers. These parameters were measured in three rotary milking parlours with herringbone type of stalls, each for 24 dairy cows. Two of these milking parlours were built in 2001 and one was built in 2009. Measurements were taken during the winter and summer periods, under extremely cold or high temperature conditions. Measurements were taken during the milking process for about two hours using suitable sensors for measurement of indoor temperature and relative humidity. The data of outside temperature and relative humidity were also obtained and compared with indoor data. The final results of the research were generalized. It is obvious from the results of measurements of selected milking parlours that heating and ventilation of milking parlours is insufficient. To set up adequate heating power, the heat balance of milking parlours was calculated. For adequate ventilation, the necessary flow of fresh air was calculated for both winter and summer periods. Also the methods of how to achieve these air flows are presented.

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759-764 P. Kic
Dust pollution in University offices
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Dust pollution in University offices

P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Kamycka 129, CZ-16521 Prague 6, Czech Republic;
e-mail: kic@tf.czu.cz

Abstract:

The aim of this paper is to present results of microclimatic research focused mainly on dust pollution in several offices of Departments in the Faculty of Engineering at Czech University of Life Sciences Prague. The attention is paid to the dimensions of the room, floor covering, furniture, equipment, ventilation, frequency of the use and period of the year. In the frame of this research the concentration of air dust was measured by special exact instrument Dust-Track aerosol monitor. After the installation of different impactors the PM¹, PM².⁵, PM⁴, PM¹0 size fractions were also measured. The obtained results of measurements were evaluated by the statistical instruments and concentrations of different size of dust particles were analyzed. Results of different indoor conditions were generalized. Based on the results of measurements practical recommendations for the design, use, cleaning and ventilation of these types of rooms and buildings were summarised in the conclusions.

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505-512 J. Papez and P. Kic
Wood moisture of rural timber constructions
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Wood moisture of rural timber constructions

J. Papez and P. Kic*

Czech University of Life Sciences Prague, Faculty of Engineering,Kamycka 129, 16521, Prague 6, Czech Republic;
*Correspondence: kic@tf.czu.cz

Abstract:

The aim of this paper is to present the methodology of measurement of moisturecontent of wood and show some results of this measurement in application on constructions ofagricultural buildings. Wood moisture can affect the durability of buildings. Measurements arein two different animal houses, which varied in design and implementation of the constructionmaterial (steel-wood and steel with wooden rafters). Both these buildings are relatively new(built in 2001 and 2009). There was measured also an older shed attached to the barn, which hasa storage and protective function. All these buildings are from spruce wood. The measurementwas based on the use of resistive sensor and capacitive sensor. Also determined was thetemperature and humidity of the air.From the results of measurements of tested buildings it is obvious that the moisture of the woodis in direct proportion with the relative humidity of the air. There are different results measuredby capacitive and resistive sensors. The suitability of the sensors for determination of woodmoisture was verified by gravimetric method, that is direct method and the results are veryaccurate. In the case of coniferous wood (especially spruce wood), there can be used withsufficient accuracy a capacitive sensor, which was used in all examined buildings. Key word: animal houses, wood, measurement, moisture content.

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