Determining the dynamics of electromagnetic fields, air ionization, low-frequency sound and their normalization in premises for computer equipment

Abstract

This paper reports a study into the quantitative values and dynamics of physical factors in premises and workplaces of stationary and portable computers. The factors that are practically not perceived by the senses of operators were investigated. It is established that modern monitors do not generate electromagnetic fields of hygienically significant levels. System units generate electric fields (18‒22 V/m) and magnetic fields (220‒245 nT) that are approaching the maximum permissible. Sources of uninterruptible power supply and fluorescent lighting systems generate excess magnetic fields (up to 2250 nT and 2300 nT), respectively. The main excessive factor for portable computers is electric fields (up to 9 kV/m), which is the cause of air deionization in the user's zone of stay. It is shown that one system unit in the normative volume of the room (20 m3) deionizes air (into 100 cm-3 positive and 200 cm-3 negative). The generation of ions by modernized laser printers and photocopiers of various models (up to 1500 cm-3 and 2800 cm-3, respectively) was investigated. The distances at which the ionic composition of the air corresponds to the background values (1.0‒1.5 m) were determined. That requires the introduction of artificial air ionization in workplaces of users and a decrease in the levels of electrostatic fields. The spectral composition and amplitudes of magnetic fields of external power supplies of laptop computers were determined. It is shown that the difference in sound levels measured on the scales "Lin" and "A" reaches 24 dB, which indicates a significant impact of infrasound on users. Membrane-type protective panels configured for maximum resonant frequencies of low-frequency sound and infrasound have been proposed

Засади Зниження Рівнів Низькочастотного Звуку Та Інфразвуку У Виробничих Та Побутових Умовах

“…Частково засіб мінімізації низькочастотного звуку надано у роботі [10]. Але ці рекомендації мають окремий характер і стосуються приміщень з комп'ютерною технікою.…”

Дослідження Рівнів Інфразвуку У Навчальних Приміщеннях Та Визначення Умов Їх Нормалізації

“…Аналіз останніх досліджень і публікацій свідчить, що значна кількість зарубіжних та вітчизняних наукових досліджень присвячена питанням джерел випромінювання інфразвуку, закономірностей його поширення і взаємодії в різних середовищах, будівлях і конструкціях, шкідливого впливу на людський організм, у тому числі у виробничих умовах, способів і засобів нормалізації інфразвуку [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Effects of rotational speed on the natural frequency of the differential bevel gear

“…A study into the quantitative values and dynamics of physical factors in premises and workplaces of stationary and portable computers. Membrane-type protective panels configured for maximum resonant frequencies of low-frequency sound and infrasound have been proposed [11]. Knowing the consequences of movement in the differential gearbox and the quantity of emitted vibrations and how to address them through the two upcoming investigations was the paper's usefulness.…”