According to ISO 7730:2005, classification is a mandatory precondition for thermal comfort assessment since the appropriate criterion depends on which category the specific work situation (SWS) investigated belongs to. Unfortunately, while the standard does include three different comfort criteria, it does not indicate how the appropriate criterion should be selected. This paper presents a classification scheme that allows thermal comfort assessment to be reliably performed in any environment. The model is based on an algorithm that calculates a score by means of a weighted product of three quantities, each one taking care of a specific, highly relevant element: the subject's thermal sensitivity, the accuracy required for carrying out the task and the practicality of thermal control. The scheme's simple modular structure can easily accommodate both changes and additions, should other hypothetical elements be identified to be as relevant to the classification scheme. The model presented allows a modulation of comfort levels across different social groups. It is so possible to provide extra care for children, elderly, pregnant women, disabled and other 'weak' categories, as required by ISO/TS 14415:2005, by setting the highest comfort level. Finally, it also widens the options for simultaneously establishing comfort conditions for different individuals performing different tasks in the same area and clarifies whose comfort should be pursued with the highest priority.
As a part of their very wide range of applications, international standards also represent an excellent technical support to the legislation on comfort and health at the workplace. The existing standards on thermal comfort and on indoor air quality both include limits of acceptability which strongly depend on the category chosen for the investigated work environment. Therefore, the same situation can easily meet compliant or largely exceed specified limits depending on which category is applied. Unfortunately, no clue is currently provided on how to select the appropriate category, and the enduser is left uninformed. In this paper, we present a method to assign limits of acceptability to any work situation whose thermal comfort and indoor air quality must be assessed. The method extends previous work developed specifically for thermal comfort and is based on an algorithm which takes into account three quantities that provide a comprehensive description of the work environment, the activity which is carried out and the sensitivity of individuals. The scheme's simple modular structure can easily accommodate both changes and additions, should other hypothetical elements be identified to be as relevant to the classification scheme.
In this paper we present the outcome of a Round Robin test carried out to validate a proposed standard procedure to measure the acceleration produced by an hand held olive harvester. Ten independent laboratories using a custom-built device were involved. The device was developed to simulate olive tree branches as far as their interaction with the harvester sticks is concerned. Collected data were analysed according to the ISO 5725-2 procedure. Accelerations measured in three of the ten laboratories were found by a cluster analysis to be statistically different from those of the remaining seven laboratories. Based on this evidence, results from the three stray laboratories were eliminated from the final sample. Laboratory data were shown to be statistically consistent with field data in the dominant front and rear X axes as well as in the rear Z axis. No statistically significant discrepancy were found for the front and the rear acceleration vector sums, which are the quantities used to quantify the occupational exposure. The procedure developed in this Round Robin test could represent a viable basis for a future test standard for hand-held olive harvesters.
Dosimetric measurements carried out on basketball referees have shown that whistles not only generate very high peak sound pressure levels, but also play a relevant role in determining the overall exposure to noise of the exposed subjects. Because of the peculiar geometry determined by the mutual positions of the whistle, the microphone, and the ear, experimental data cannot be directly compared with existing occupational noise exposure and/or action limits. In this article, an original methodology, which allows experimental results to be reliably compared with the aforementioned limits, is presented. The methodology is based on the use of two correction factors to compensate the effects of the position of the dosimeter microphone (fR) and of the sound source (fS). Correction factors were calculated by means of laboratory measurements for two models of whistles (Fox 40 Classic and Fox 40 Sonik) and for two head orientations (frontal and oblique).Results sho w that for peak sound pressure levels the values of fR and fS, are in the range -8.3 to -4.6 dB and -6.0 to -1.7 dB, respectively. If one considers the Sound Exposure Levels (SEL) of whistle events, the same correction factors are in the range of -8.9 to -5.3 dB and -5.4 to -1.5 dB, respectively. The application of these correction factors shows that the corrected weekly noise exposure level for referees is 80.6 dB(A), which is slightly in excess of the lower action limit of the 2003/10/EC directive, and a few dB below the Recommended Exposure Limit (REL) proposed by the National Institute for Occupational Safety and Health (NIOSH). The corrected largest peak sound pressure level is 134.7 dB(C) which is comparable to the lower action limit of the 2003/10/EC directive, but again substantially lower than the ceiling limit of 140 dB(A) set by NIOSH.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.