5.6 Safety precautions when working with a computer
Personal computer is the appliance. From other electrical appliances it is different in that it provides an opportunity for long-term operation without disconnecting from the mains. In normal operating mode, the computer may be in a mode with reduced power consumption in the standby or idle mode request. In connection with the possibility of continuous operation without shutting down the computer from the electrical outlet should pay special attention to the quality of the organization of power. Impermissible use of substandard and worn components in the electrical system, as well as their surrogate substitutes: outlets, extension cords, adapters, tees. It is unacceptable to modify their own data port plugs that meet other standards. Electrical contacts outlets should have no mechanical loads associated with the connection of massive components (adapters, tees, etc.). All cables and wires shall be located at the rear of the computer and peripheral devices. Their placement in the work zone member is not allowed. Do not make any transactions associated with connecting, disconnecting or moving the components of a computer system without loss of power. The computer should not be used near electric heaters and heating systems. It is unacceptable to place on the system unit, monitor, and peripherals foreign objects: books, sheets, towels, blankets to protect against dust. This leads to a permanent or temporary block its air vents. Forbidden to introduce foreign objects into the ventilation slots or operational components of a computer system. Features of the power of the monitor. The monitor has elements that can maintain a high voltage for a long time after being disconnected from the network. Opening the monitor user is unacceptable under any circumstances. This is not only dangerous to life, but also technically useless, as there is no monitor inside organs, adjusting or setting which the user can improve its performance. Opening and maintenance of monitors can be made only in special workshops.
When you work with your computer you need to know the following measures:
1) must be in the room must be enabled and the light should be lit table lamp;
2) when working with a computer is necessary to observe the correct posture;
3) the distance from the eyes of the monitor should be at least half a meter;
4) how long the PC should not exceed 2 hours
5.7 Calculation of artificial light and noise workplace laboratories "NIT"
Objectives: To calculate the parameters of the artificial lighting. Determine the intensity of the sound sources to the levels of intensity, and to find the total noise level for all sources. All coefficients are taken from the data sheet [10]
We consider task - lighting, it provides regulatory light levels indoors and work sites outside of buildings. The ultimate goal is to determine the type of lamps and the number of lamps. Since the minimum target of discrimination at work with a PC pixel - one point of light, and its size is 0.28mm, it has to deal with the visual work of very high accuracy, a level II of visual work. And depending on the software used can be dealt with, both directly and with reverse contrast and contrast the nature of the object and the nature of the background can be anything: light, medium, dark. It should also be noted that the duration of the visual work is more than half of the working day. On the basis of these data, we conclude that the visual work has a level II with subclass "in". General lighting is 500 lux and 2000 lux illumination combined, including 200 lux lighting.
Since the work PC does not belong to the category of very fine, choose a system of general lighting.
Bulb Type LTB40; lamp power Pl = 40 W
Luminous flux Fl = 2200 lm
The luminaires with tubular fluorescent lamps are placed parallel to the wall with windows. Fixtures are arranged in rows, docking with each other.
Plans location of fixtures and their vertical orientation (Figure 16):
hn and hp - defined;
hn = 3 m
hp = 0.8 m
The distance from the floor to the fixture:
hc = 0,2 (hn-hp) = 0.44 m; (5.1)
The distance from the working surface to the lamp by formula
hcp = hn - hp - hc = 1.46m; (5.2)
= 1,5 (for fluorescent lighting fixtures);
lc= hcp (5.3)
lc = 1.5 * 1.46 = 2,19 m - the distance between the centers of the lamps.
