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tutorial 11
Prodi Teknik IndustriFakultas Teknologi IndustriUniversitas Islam IndonesiaTahun Ajaran2016/2017
physical work environment 2
PHYSIOLOGY AND WORK MEASUREMENT
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PHYSICAL WORK ENVIRONMENT 2 2016
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Physical Work Environment II
Physical work environment is everything that exists around the workers which influential in
running the duties imposed, for example lighting, temperature, space, security or music
(Nawawi, 2001). In this tutorial, students will observe the influence of temperature and noise
to output of the workers.
A. Objectives
1. Students able to know the influence of temperature to the output of work and the
optimum level temperature to work.
2. Students able to know the influence of temperature with the output result.
3. Students able to know and understand the influence of noise level in work
environment of the task.
4. Students able to know how to measure temperature and noise level using
thermometer and sound level meter.
5. Students able to analyze the optimum design of physical work environment.
B. Input and Output
Input:
a) Subject Description
b) Output Data Summary
Output:
Comparative analysis of productivity by treatment with different physical working
environment.
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C. Tutorial Tools and Producedure
a) Climate Room
Climate Room at Work Systems Design and Ergonomics UII is the laboratory facility
that used to simulate various states of physical work environment, such as simulated
lighting, temperature, noise, and vibration.
Figure 1. Climate Room at WSD&E Laboratory UII
b) Air Conditioner (AC)
AC is used to perform simulations related to temperature with the temperature set
according to the scenario.
c) Speaker
Speakers are used to give effect of noise for the operator to complete the work.
Figure 2. Speaker
d) Thermohygrometer
Thermohygrometer is a tool that designed for measure the temperature of a physical
environment labor.
Figure 3. Thermohygrometer
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Here is how to use the temperature measurement using Thermohygrometer:
1) Place the sensor Thermohygrometer on where you want to measure.
2) Waiting for output until 5 minutes.
3) Observe the scale on the digital Thermohygrometer.
e) Sound Level Meter
Sound Level Meter is a tool that designed to measure the noise of an object.
Figure 4. Sound Level Meter
Here is the step of measuring noise using sound level meter:
1) Select the right SLM position selector with the type of noise.
2) Choose the range of noise intensity selector.
3) Determine the measurement area.
4) Measure dB sound pressure level for 10 minutes for each measurement interval
with readings were taken every 5 seconds
5) Write down the measurement result and calculate the average noise (Leq)
f) Laptop
Laptop used to run software Design Tool and also for data processing lab.
Figure 5. Laptop or Computer
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g) Design Tool Software
Design Tool Software used as an application for helping activities to measure short-
term memory. Results (outputs) of the activity will be data to be analyzed.
Figure 6. Design Tool Software
h) Observation Sheet and Stationary
Observation Sheet is a sheet in which the practitioner writes the data obtained during
the tutorial.
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D. Theoretical Review
1) Temperature
Temperature is physics quantity which is a measure of the heat or the coldness of
a˚condition. According to Sutalaksana (1979), to review different level of temperature will
give a different affect, is as follows:
1. 49˚C, the temperature can be detained for about an hour. However, it is above
the physical and mental abilities.
2. 30˚C, mental activity and comperehension decreasing slowly and tend to make
mistakes in work also arising fatigue.
3. 24˚C, optimum working condition.
4. 10˚C, extreme physical behavior began to emerge.
Based on an investigation has obtained that the productivity of human labor will reach the
highest level at a temperature of 24 to 27 degrees Celsius (Sutalaksana. 1979)
1.1 Health Problems Caused by Exposure of Temperature
According Tarwaka (2004) health problems caused by exposure of high temperature can be
explained as follows:
a. Behavioral disorders and work performance such as fatigue, doing break stolen, etc.
b. Dehydration
Dehydration is the excessive loss of body fluids caused by fluid replacement is not
enough or because of health problems. In the body fluid loss <1,5% there is no visible
symptom, fatigue appears earlier and dry mouth.
c. Heat Rash
Circumstances such as prickly heat or prickly heat, skin itching due to skin continuously
wet conditions. In this condition, the workers need to rest in a cooler and use powder
busting a sweat.
d. Heat Cramps
Is body muscle spasms (hands and feet) due to perspiration, which causes the loss of
sodium from the body that is most likely caused by drinking too much with little sodium.
e. Heat Syncope or Fainting
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This situation is caused by blood flow to the brain is not enough because most of the
flow of blood under the skin or peripheral surface caused by exposure to high
temperatures.
f. Heat Exhaustion
This situation occurs when the body loses too much fluid or ion loss. Symptoms of dry
mouth, very thirsty, weak, and very tired. This disorder usually experienced by workers
who have not adapted to hot temperatures.
g. Heat Stroke
This situation occurs when the body becomes very hot where sweat glands and other
organs do not function normally. This situation is most dangerous.
2) Noise
Noise is a pressure which can be detected by ears or longitudinal wave that propegate
through media such as liquid, solid and gas. According to Decree of The Ministry of
Environment No.Kep.Men-48/MEN.LH/11/1996 noise is unwanted noise from operations
and activities to the level of a certain time that can cause human health problems and
environmental discomfort. According to Firdaus, et al. (2009) had explained there are three
aspects that determine the quality of noise which give affect to human, i.e:
a. The length of time the sound is heard.
b. The intensity is usually measured in decibels (dB), which shows the amount of
energy flow per unit area.
c. Frequency sound indicates the number of sound waves through the human ear in a
second (the number of vibrations per second or hertz)
2.2 Noise Limit
Delivering an information or a simple news will be understood if it levels as high as 10 dB
or higher than the noise threshold. However, for more complex information consisting of
words less known, the level of the conversation should be 20 dB or higher than the threshold
noise. The level talks are categorized as follows:
1. Daily Talk : 60-65 dB
2. Talk in a seminar : 65-75 dB
3. Screaming : 80-85 dB
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Those values are applied at a distance of 1 meter from the speaker. Moreover, can be
concluded that communication would be very difficult to on the limit of noise above 80 dB.
This distance can be reduced until the speaker had to shout in the ear of a listener (Nurmianto,
1996).
The limit of noise exposure time per working day based on the intensity of noise
received by workers is as follows:
Table 1. NAB Classification
Prolonged expossure per day (hour) Level of noise (dB)
24 80
16 82
8 85
4 88
2 91
1 94
½ 97
¼ 100
Note: It’s prohibited to be exposed to more than 140 dB although momentarily
Source: Kepmennaker No 51 Tahun 1999
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2.3 Noise Calculation
From the noise measurement, the obeserver has obtained this following data:
Table 2. Noise Measurement Recapitulation
Based on the table above, there are 120 datas that has collected from the physical work
environment observation with exposure to certain sound in 10 minutes. Level of noise
measurement inflicted by using sound level meter in every five seconds. To get the
recapitulation data listed on table 3, the calculation based on The Ministry of Environmental
of Indonesia Nomor: KEP-48/MENLH/11/1996 as follows must be done:
1. Calculate the range (r)
𝑟 = 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑠𝑐𝑜𝑟𝑒 − 𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑠𝑐𝑜𝑟𝑒
Then the range of recapitulation data above is:
𝑟 = 75,2 − 47,5 = 22,7 𝑑𝐵
2. Calculate the number of the class (k)
𝑘 = 1 + 3,3 log 𝑛
Then the number of the class based on the recapitulation data is:
𝑘 = 1 + 3,3 log 120 = 7,9 = 8
3. Calculate the interval of the class (i)
𝑖 =𝑟
𝑘
Then the interval on the data recapitulation is:
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𝑖 =47,5
7,9= 6,04
4. Create The Frequency Distribution
The following table is based on the frequency distribution.
Tabel 3. Frequency Distribution
No Interval Median Frequency
1 32,8 - 38,84 35,82 11
2 38,94 - 44,98 41,96 22
3 45,08 - 51,12 48,1 15
4 51,22 - 57,26 54,24 17
5 57,36 - 63,4 60,38 13
6 63,5 - 69,54 66,52 18
7 69,64 - 75,68 72,66 14
8 75,78 - 81,82 78,8 10
5. LTM5 Calculation
LTM5 = 10 𝑙𝑜𝑔 1
𝑛𝑇𝑛. 100,1𝐿𝑛
Then the LTM5 calculation based on the data recapitulation mentioned in table 3 is as
follows:
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E. Tutorial Procedure
Below is the tutorial Physical Work Environment 2 procedure:
Figure 8. Tutorial Procedure
Start
Theory & Posttest
Determine the
operator
PRETEST
Normal
temperature
PRETEST
Normal noise
POSTTEST
Cold temperaturePOSTTEST
High noise
Data Processing
Data input
Result Analysis
Qualified Report
ACC Assistant
Upload report to
the website
Finish
No
Yes
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Figure 8 above shows the tutorial flowchart of Physical Work Environment 2. In
processing the data, observers will process the data to know whether there is a significant
difference between two correlated samples (pre test and post test). Therefore, Paired
Sample T-test will be used to processing the data.
Paired Sample T-Test is a part of parametric statistics, therefore the data should be
normal distributed first before it can be continued to the T-tes.Thus, normality test is
needed.
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REFERENCES
Dewi, M. P. (2009 ). Analisis Pemaparan Intensitas Kebisingan di Unit Compressor
dan Unit Cooling Tower PT. Indo Acidatama Tbk, Kemiri, Kebakkramat,
Karanganyer.
Keputusan Menteri Negara Lingkungan Hidup Nomor: KEP-48/MENLH/11/1996.
(1996). Jakarta: Kementrian Lingkungan Hidup.
Nurmianto, E. (1996). Ergonomi: Konsep Dasar dan Aplikasinya. Surabaya: Guna
Widya.
Oktri Mohammad Firdaus, N. J. (2009). Analisis Pengaruh Lingkungan Kerja terhadap
Aktivitas Pekerja. 5th National Industrial Engineering Conference, 484-491.
Sutalaksana, I.Z., Anggawisastra, R. & Tjakraatmadja, J.H. (1979). Teknik Tata Cara
Kerja. ITB, Bandung.
Tarwaka, Bakri, Sudiajeng. (2004). Ergonomi Untuk Keselamatan, Kesehatan Kerja
dan Produktivitas. UNIBA Press. Surakarta
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