7. Safety and environmental
Project
7.1. Analysis of working conditions
in rooms with PCs
Subject of this graduation project is a writing program for
microcomputer by using cross-development.
Consequently, it is understood the work of a programmer with PC
for a long time, and then a permanent job with the finished
user program - the operator of an ultralight.
The complication of working conditions in connection with
the use of computer technology has high requirements for human
organism.
Workstation computer programmer and the user is a room with
a PC (computer center), which in most cases used the universal
personal computer (PC). Currently, the standard is the
classification of hazardous and hazards according
GOST12.0.003-74 * . Premises, which is used by the PC to
have a significant impact on the safety of the user and
therefore they must comply with SanPiN 2.2.2.542-96 and SNIP
2.09.04-87 [9].
Employees are facing the data center to the influence of
such dangerous and harmful factors, such as:
■ suboptimal microclimatic conditions;
■ high level of noise;
■ insufficient lighting, etc.
When you work directly for the operator
computer monitor on his act and such hazards as:
■ low-energy X-rays;
■ ultraviolet radiation;
■ infrared radiation;
■ Static electricity;
■ alternating electric and magnetic
field.
The presence of electrical lighting network creates a risk
of electric tokom.Takzhe manifest some psycho-physical factors:
■ mental strain;
■ surge of visual and auditory
analyzers;
■ monotony of work;
■ emotional overload.
The impact of these factors
leads to progressive fatigue,
causing a reduction in health
workers' data centers.
When you work with computers in the computer center there is
a danger of fire. Hazards of fire:
■ sparks;
■ Increased ambient temperature and subjects;
■ Reduced oxygen concentration in the
air;
■ toxic combustion products.
The room, which establishes the PC,
shall be equipped with air conditioning for
maintain optimal microclimatic
conditions. But at the same time air conditioning might
create suboptimal conditions for working, for example, noise,
increase or decrease in humidity or
temperature. Requirements for Workplace Air
zone are listed in Table 7.1.1 [11].
Table 7.1.1
Tempera-Relative-rate
Period, the category of relative motion of the tour
theory, the air moist air
work ° C, not in the st-m / s
Safety requirements more,%
Easy-22Ў24 40Ў60 0.1
Cold-1a (21Ў26) (75)
LIMITED Easy-21Ў23 40Ў60 0,1 (0,2)
1b (20Ў24) (75)
Easy-23Ў25 40Ў60 0,1 (0,2)
Warm 1a (22Ў28)
Easy-22Ў24 40Ў60 0.2
1b (21Ў28) (0,1 Ў0, 3)
The main PC devices, creating
high level of noise, are the cooling fan in the power supply of
computers and dot matrix printer at work.
In industrial premises with PC
Vibration shall not exceed the established
allowable according SanPiN <Residential and
industrial buildings>. Standards acceptable
vibration are shown in Table 7.1.2 [11].
Table 7.1.2
Valid values
Srednegeometri-vibration
cal frequency of vibration of vibration octave bands, faster
speed
Hz
m / s ¤ DB m / s ¤ dB
2 5.3 25 4.5 Ў10 Ў10 79
4 5.3 25 2.2 Ў10 Ў10 73
8 5.3 25 1.1 Ў10 Ў10 67
16 1.0 31 1.1 Ў10 Ў10 67
31.5 2.1 37 1.1 Ў10 Ў10 67
63 4.2 43 1.1 Ў10 Ў10 67
Corrected values of 9.3 and 2.0 Ў10 Ў10 30 72
their level, dBW
The noise level in rooms with broken equipment should not
exceed 40 dBA, and during the operation - 50 dBA. Relevant
sound pressure levels are determined according to CH 3077-84
[11] (Table 7.1.3).
Table 7.1.3
Sound pressure levels, decibel levels
sound
Mean frequency is equivalent to
octave bands, Hz valence
levels
63 250 1000 4000 audio
31.5 125 500 2000 8000 dBA
- 63 52 45 39 35 32 30 28 40
86 71 61 54 49 45 42 40 38 50
Achieving the goal - safe operation
PC - requires the definition of maximum permissible levels of
electromagnetic radiation, providing security at that distance
from the monitor, which usually peaks the work is a computer
user. Options Safety performance of the class described
in GOST 50949-96 and GOST R 50948-96
<Visual display products for individual use. General ergonomics
and safety requirements>. Standards for levels of electric and
magnetic Fields describes SanPiN 2.2.2.542-96 (Table 7.1.4)
[11].
Table 7.1.4
Tension AC Acceptable
electric field to a value
radius of 50 cm from the screen, no more
frequency band
¡The 5 Hz 2 kHz 25 V / m
¡The 2 kHz 400 kHz 2.5 V / m
Magnetic induction,
frequency band
¡The 5 Hz, 2 kHz, 250 nT
¡The 2 kHz, 400 kHz 25 nT
Surface electrostatic potential of the display 500
Particular attention should be paid to the monitor
osveschennosti.Rabota PC is hard visual work, and non-optimal
lighting can greatly enhance eye fatigue, and prolonged
exposure to significantly reduce visual acuity. The coefficient
of natural illumination levels shall comply with the provisions
of 23.05-95 snip <Natural and artificial lighting>. Artificial
lighting in the room with the PC should perform general system
of uniform illumination. In accordance with SNIP 23.05-95
illumination on the table surface in the zone placement of the
working paper on the system General lighting should be 300Ў500
lux. Ripple factor should not exceed
5%, which is achieved by using gas-discharge lamps in the HF
PRA.Yarkost fixtures general lighting in the area of the
angles of radiation from 50 to 90 ° from the vertical in the
longitudinal and transverse planes should not be Over 200 cd /
m ¤.
One of the most serious is the danger of electric shock. From
Electrical lighting network feed on all
PC components, as well as established in the data center air
conditioners, electrical and other equipment. Applicable
measures and means of electrical must ensure that the
requirements GOST 12.1.038-82 * defines the maximum
valid values for contact voltage Upd and flowing through the
human body current Ipd. The values of Upd and Ipd Accidental
mode (eg, for the closure phase network
on the metal case) time-dependent effects of current t. In the
case of healthy adults with the technical
means of friction at emergency operation
values of Upd and Ipd must comply
specified in Table 7.1.5 Standards for the production of
electrical [11].
Table 7.1.5
Domestic Production
t, c electrical electrical
Upd, B Ipd, Upd mA, V Ipd, mA
0.01 ..
.. 0.08 550 650 220 220
0,1 340 400 200 200
0,2 160 190 100 100
0.4 120 140 55 55
0.5 105 125 50 50
0.6 95 105 40 40
0.7 85 90 35 35
0.8 75 75 30 30
1.0 60 50 25 25
Over
1,0 20 6 12 12
Risk of electric shock
largely depends on operating conditions
equipment, describing the premises. For
achieve an acceptable level of electrical safety requires that
in a room with PC no conditions that create, according to the
Rules for Electrical and GOST 12.1.019-79 *, enhanced or special
Hazards:
■ humidity (relative humidity exceeds 75%);
■ high air temperature, continuously or intermittently (more
than 1 day) exceeding +35 ° C; ■ conductive (non-insulating
coating) sex; ■ conductive dust;
■ reactive or organic
environment (aggressive couples, sediment, or mold, destroying
insulation and conductive part);
■ ability to simultaneously touch the person to have a
connection to the land metal structures of buildings, machinery
and etc. and metallic elements (enclosures,
grounding terminal or vanishing, jacks)
electrical equipment that may be
energized when the damaged working
isolation.
Measure of protection against electric
shock:
■ double insulated electrical installations -
a collection of work (basic) and protective (additional)
insulation, which are available at a touch electrical parts do
not acquire a dangerous voltage is damaged only a protective or
Working isolation; ■ Reinforced insulation - it's better to
to ensure human safety
operational insulation elements under
voltage equivalent to double insulation
the degree of reliability (protection);
■ neutral - it is a deliberate connection of metallic parts of
electrical installations (buildings), which may be under
voltage for insulation damage, with earthed neutral source with
protective earth conductor; ■ Safety off - it's a fast
defense, the automatic shutdown of electrical installations in
the event there danger of electric shock, human [11].
Fire hazard areas with a PC is determined by the
peculiarities of running into them processes, properties of
substances and materials used, as well as conditions of their
treatment. By explosion and Fire safety facilities are
classified in categories A, B, V1ЎV4, G and D. The premises
with PC often belong to the category B.
Fire hazard areas depends on
the magnitude of his fire on the load Q (MJ)
which includes various combinations (mixture) and hard
combustible liquids, solids and materials:
N
Q = ∙ G · Q,
i = 1 i Hi
where G - the number of i-th material fire
i
load, kg;
Q - lower heating value of the i-th material
Hi
rial, MJ / kg.
Definition of fire-category room (V1ЎV4) by comparing the
maximum value of the specific fire load space with the value of
g specific fire load ∈ H, given
Table 7.1.6 [11].
Table 7.1.6
Category B1 B2 B3 B4
premises
g, MJ / m ¤ More 1401Ў 181Ў 1Ў
n 2200 Ў2200 Ў1400 Ў180
Specific fire load ∈ H is determined from the relation: g =
Q / S, where S -
n
footprint of fire load, m ¤.
Considered the room has an area of
40 m ¤. Paul it is covered with thick planks
1.5 cm, placed in a room 8 wooden tables weighing 35 kg, wooden
cabinet weighing 200 kg and 2 wooden partitions
weighing 50 kg. Thus, we obtain:
Weight parquet: 40.520.0, 015 = 312 kg.
Weight of wooden furniture: 8.35 200 2 × 50 =
= 580 kg.
Lower heating value of wood is
12.4 MJ / kg. Specific fire load
premises is:
(312 580) · 12.4
Q = = 276,52 MJ / m ¤.
40
The room is classified as fire B3.
For the primary means of fire fighting
rooms with PCs include a variety of carbon dioxide, aerosol,
powder extinguishers are designed to extinguish fires and fires
in the early stages of their development.
7.2. Selecting the method of conditioning
room with PC
Features of operation of electronic
equipment (including PCs) require
the use of advanced heating,
ventilation and air conditioning.
The most difficult room in terms of
implementing the necessary microclimatic
parameters that provide comfortable conditions for staff, a
computer room. Indoor climate is a combination of temperature,
humidity and velocity motion vozduha.Soglasno GOST 12.1.005-88
work at the computer center requires
energy up to 139 watts, that allows us to assign it to category
1a light physical works, and for warm season
is optimal temperature
23Ў25 ° C at a relative humidity 40Ў60%
and air speed up to 0,1 m / sec.
Technical requirements for the parameters of the
microclimate in the areas of PC are less stringent, and as a
settlement can be used by the optimal microclimate parameters
in the workplace.
Outside ∈ H
air
PC PC>
tn
> Tvn
tc>
>>>
BC
PC PC PC
Depending on the parameters and types of computers use
different conditioning circuits and types of air conditioners.
For areas that contain Computers may be used for household
air-conditioners installed in the windows and feed the
processed outdoor air directly into computer room data center.
Scheme air conditioning with air-conditioning of this type is
shown in figure 7.2.1 [9].
We perform an approximate calculation of the required number
of air conditioners that are required to implement the chosen
scheme of air, which is used for PC and SM computers.
Table 7.2.1
Characteristics of air conditioners
Computer and computer rooms
Characteristics of the KTA KTA KTA BK BK BKristiki 1-10 1-25
1-8 1500 2000 2500
Dietel produ-4 6,3 x 2x
sequence of 10 3 3 400 500 630
Air, x10 x10
3
m / h
Produ tivity of 46.5 29 9.9 1.74 2.3 2.9
cold,
kW
Type to use air conditioner: BC-1500
His performance:
3
■ By Air: G. = 400 m / h;
■ in the cold: Q. = 1.74 kW.
Determine the total power Qevm, which consists of power
released Computers, electrical appliances, as well as from the
heat man of 75 Tues
One PC with a printer allocates 200 watts.
In the computer center are 5
PC, 12 fluorescent bulbs 60 watts each. Thus, the total heat
dissipation is:
Q = N q + N q + N q =
COMPUTER COMPUTER COMPUTER Chel Chel LL
= 5.200 8 75 12 · · 60 = 2.32 kW.
Microclimate parameters inside the building
- Tvn temperature and humidity WHF
determined according to GOST 12.1.005-88 <General
hygiene requirements for working zone air>. For warm
, these parameters are determined by category 1a light physical
work and comply with:
t = 23 .. 25 ° C, r = 40 .. 60%.
any any
Calculating the number of air conditioners is calculated as
follows:
3600 · Q
Computer
N ¢,
3600 · Q
to
1,2 G C · (t-t +)
to any any n 1,2 G C
to Mr.
where the feminine and CH - heat capacity of chilled
air-conditioning and outdoor air, respectively.
Heat of air is determined by
formula:
1,8 d 623fR
C = 1,005 +; d =;
1000 B- Qk.tabl, the estimated number of air-conditioners
increase is not required.
Total air flow through the air conditioner
determined by the formula:
G = G (1 + Z) (kg / h)
Mr. Computer
where Z - health factor, Z = 0,1 Ў0, 2 =
= 0.15.
3600 · Q
PC 3600.2, 32
G = = = 573,63 kg / h;
Computer C (t-t) 1,04 · (24-10)
any given
G = 573,63 · (1 0.15) = 695.67 kg / h.
n
The minimum required amount of outdoor air supplied to the
premises shall not be less than the required sanitary standards
for submission to one cheloveka.V comfortable air-conditioning
systems use sanitary norms feed outside air per person shall be
30 kg / h. Then, for the premises:
G = 30N = 30.8 = 240 kg / h.
n.min Chel
Since ∈ H> Gn.min, the estimated number of air-conditioners
increase is not required.
Thus, the calculation shows that for
the effective maintenance of microclimate parameters inside the
data center out of five jobs is necessary to use two air
conditioners BC-1500. This amount of air conditioning provides
the necessary performance for air and cold.
8. Conclusion
The developed software
to manage the specialized logic analyzer will greatly simplify
the process of setting devices connected to a common bus, at
the stage of control after production and also in the process
of setting and operation. The use of this software will
significantly reduce the time spent on commissioning of the
equipment.
In the capstone project shows the functional diagram of the
device and describe the control algorithms specialized logic
analyzer; on these algorithms, a program with given functions
and parameters.
To improve the performance of the system developed and
implemented a special method of compression of transmitted
data, focused on the use of a system of required performance
and optimized to compress digital signals.
The complexity of the development of significantly
reduced through the use of cross-protection
Programming Asm51Edit 2 and monitoraotladchika Debugger-51. The
results of debugging programs in the form of graphs and dump
signals before and after the issue of data kompressiey.Dlya
simplify the process of generating test sequences of signals as
well as verification of the returned signal with the original,
in Delphi 5 has been developed A special program generator with
built-in decompressor blocks of data response messages ALS.
9. Literature
1. Boborykin AV etc. Single chip microcomputers: a guide .- M.:
, 1994 .- 400 with.
2. Stashin VV, Urusov AV Mologontseva
O.. Design of Digital Devices
on-chip microcontrollers. -
MM: <Energoatomizdat>, 1990. - 224.
3. Brodin, VB, Shagurin II microcontrollers. Architecture,
programming, interface .- M.: <ECOM>, 1999 .- 400 sec. 4.
Timothy Bell, Ian H. Witter, John G. Cleary. Modeling for text
compression.ACM Computer Surveys. Vol. 21, No.4 (Dec. 1989),
pp.557-591. 5. GP Bogdanov and dr.Metrologicheskoe provision
and operation of the measuring technique. Ed. VA Kuznetsov .-
M.: <Radio and communication>.
6. VI Pustovarov. Assembler: programming and analysis of the
correctness of computer programs .- Kiev.: , 2000 .- 480
sec. 7. K. Brindley. Electronic instrumentation. Trans. from
English. YF Arhiptseva. Ed. AP Fomin. - M.:
<Energoatomizdat>, 1989 .- 126 sec.
8. Safety and environmental project:
methodological instructions for undergraduates.
Comp. V. Zaitsev .- Ryazan, RGRTA, 1995 .- 12
with.
9. Air conditioning in data centers: guidelines to the diploma
design. Sost.V. I. Kremnev, NI
Fedotov .- Ryazan, RRTI, 1990. - 8.
10. Control of noise in data centers: guidelines to the diploma
проектированию.Сост.Н.И.Федотов .- Ryazan
RRTI, 1989 .- 11 p..
11. Securing User
when working with PC.: Tutorial. Comp.
UV Zaitsev, VI .- Kremnev, Ryazan, RGRTA,
2000 .- 75 sec.
12. Economic issues of design.
Calculations of economic efficiency in the diploma projects:
guidelines diploma in engineering. Comp. EV
Misnik, N. Prudnikov. - Ryazan, RGRTA,
2000 .- 16.
13. Typical standard time for programming problems for
computers.: Ed. M. Chinyakova .- M.: <Economy>, 1989 .- 125 sec.
14. Feasibility study of the graduation projects.: Under red.V.
K. Bekleshova. - M.: <High School> 1991. - 176.
15. E. Povalyaev. Archivers. - ComputerPress 2'2002.
16. Control program logic analyzer MWI on the PC. Terms of
Reference. - Ryazan, Federal State Unitary Enterprise RKB
<Globe>, 2000. 17. C. Teixeira, C. Pacheco. Delphi 5. Guide
razrabotchika.2 ie: Per.s angl.M.: Publishing House <Williams>,
2001 .- 1824 with.
18. B. Hoffmann, A. Homonenko. Delphi 5 .- SPb.:
, 2000. - 800.
10. Applications
Appendix 1. List of abbreviations and conventional
notation
■ Akian - kontrolnoispytatelnaya automated equipment;
■ AC - an automated system;
■ BSA - the flow-chart;
■ DOSE - dual-port RAM;
■ DOS - Disk Operating System;
■ DS - decoder;
■ CPC - the operation code;
■ LA - logic analyzer;
■ MMI - intermodule interface;
■ MC - machine cycle;
■ RAM - random access memory;
■ OMEVM - single-chip microcomputer;
■ OS - return message;
■ OEVM - single chip computer;
■ ROM - read only memory;
■ software - software;
■ EPROM - EPROM;
■ POOL - PC control software logic analyzer;
■ PC - personal computer;
■ RON - general purpose registers;
■ WP - Working Draft;
■ EMR - electronic equipment;
■ CAD - computer-aided
design;
■ SC - Synchronize combination;
■ ALS - a specialized logic
analyzer;
■ SMC - self-control;
■ TOR - Terms of Reference;
■ TA - Technical Project;
■ TS - Schmitt trigger;
■ SHA - address bus;
■ SM - Data Bus;
■ computer - electronic computer;
■ EP - conceptual design;
■ MCS-51 - a family of microcontrollers,
includes chip AT89C52;
■ RG - register;
■ RLE - Run Length Encoding (encoding
length of the repeats);
■ SFR - Special Function Registers (registers, special
functions).
[Prim.izdateley: Annex 2 and 3, as well as
graphic material sm.v disk archive]
