Sensor & Actuator

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INTRODUCTIONGeneral defnition o sensor & actuator

The main components o industrial automation are sensor, actuator and

controller. Our main discussion here is limited to sensor and actuator only. What

is exactly sensor and actuator? As the name implies, sensors are devices that

sense the presence or absence o obects.

!i"ure # $ensor %$ource ?????'!rom the f"ure above (e )no( that sensor is a device that receive input si"nal,

process it and "enerates output. While American *ational $tandards +nstitute

says that sensor is a device (hich provides a usable output in response to a

specifed measure.$o (e can say that sensor is sophisticated device that are reuently used

to detect and respond to electrical or optical si"nals by converts the physical

parameter %or example temperature, blood pressure, humidity, speed, etc.' into

a si"nal (hich can be measured electrically. $ensor capable o convertin" any

physical uantity to be measured into a si"nal (hich can be read, displayed,

stored or used to control some other uantity. This si"nal produced by the sensor

is euivalent to the uantity to be measured. $ensors are used to measure a

particular characteristic o any obect or device. !or example a thermocouple, a

thermocouple (ill sense heat ener"y %temperature' at one o its unction andproduce euivalent output volta"e(hich can be measured by a voltmeter. -ore

the temperature rise, hi"her the volta"eread by the voltmeter. All sensors need

to be calibrated (ith respect (ith some reerence value or standard device or

accurate measurement.-ean(hile, actuator is a type o motor or movin" or controllin" a

mechanism or system. +t is operated by a source o ener"y, typically electric

current, hydraulic uid pressure, or pneumatic pressure, and converts that

ener"y into motion. An actuator is the mechanism by (hich a control system acts

upon an environment. An actuator is somethin" that converts ener"y into motion.

+t also can be used to apply a orce. An actuator typically is a mechanical devicethat ta)es ener"y / usually ener"y that is created by air, electricity or liuid /

and converts it into some )ind o motion. That motion can be in virtually any

orm, such as bloc)in", clampin" or eectin". Actuators typically are used in

manuacturin" or industrial applications and mi"ht be used in devices such as

motors, pumps, s(itches and valves.0xplain the types o sensor & actuator 1 examples2ased on the properties here are several types o sensor as listed belo(.

3roximity sensor

This type o sensor uses an electronic feld to detect (hen an obect

is near. There is no physical contact bet(een the obect and the sensor.+nductive proximity sensors detect only metal obects. 4apacitive proximity

sensors can sense both metallic and non5metallic obects. Thin) o a
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manuacturin" process (here the ali"nment o a part is critical. A proximity

sensor can be used to ma)e sure the part is ali"ned (ithin a certain

tolerance. + the part is not properly ali"ned, the proximity sensor (ill be

tri""ered. This type o sensor is "enerally used to sense at distances less

than one inch.3roximity sensors are used in a variety o applications. 4onsider

these 3roximity sensors can be used to detect the end o travel on apositionin" table, to determine speed by countin" a "ear6s teeth, or be

used to chec) i a valve is ully opened or closed. 3roximity sensors can be

used to detect the presence or absence o a metallic (or) piece or metallic

pallets on conveyor lines. When a robot arm s(in"s around or a pic) and

place operation, a proximity sensor ma)es sure the arm actually has a part

in its "rippers.

Photoelectric sensor

This type o sensor uses li"ht to detect the presence or absence o

an obect. A Thru52eam photoelectric sensor uses t(o devices %a li"ht

source and a detector' acin" each other. 7etection occurs (hen an obectbloc)s or brea)s the beam o li"ht passin" bet(een them. A 8etro5

8eective %8eex' sensor emits a li"ht beam that is reected bac) to the

sensor rom a retro reector as sho(n in f"ure 9. When an obect bloc)s

the beam bet(een the sensor and the retro reector, detection occurs. A

7i:use 8eective sensor emits a li"ht beam that must be reected bac) to

it by the tar"et obect itsel or detection to occur %f"ure ;'.-ost electric "ara"e door openers include a photoelectric sensor or

saety reasons. + the photoelectric sensor6s beam is bro)en as the door is

"oin" do(n, the sensor si"nals the door opener to reverse the direction o

the door. While environmental actors can a:ect photoelectric sensors,these devices have a lon" sensin" ran"e. The obects they detect can be o

any material.

!i"ure < 3hotoelectric sensor mechanism %source ????'

$ome types o actuators are sho(n belo( =ydraulic %rotary' actuator


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This type o actuator o:ers the beneft o a lon" lie. =ydraulic actuators

consist o a cylinder or uid motor that utili>es hydraulic po(er to acilitate

mechanical process. The mechanical motion "ives an output in terms o linear,

rotary or oscillatory motion. The hydraulic actuator also allo(s or very precise

control o the movement produced. +n linear hydraulic actuators, a typical set5up

is made up o a hollo( cylinder that contains a liuid, usually oil, and a piston

that is inserted in it. When pressure is applied onto the piston, obects can bemoved by the orce produced.

=ydraulic actuators can be operated manually, such as a hydraulic car

ac), or they can be operated throu"h a hydraulic pump, (hich can be seen in

construction euipment such as cranes or excavators.

3neumatic actuators

This actuator (or) on the same concept as hydraulic actuators except

compressed "as is used instead o liuid. 0ner"y, in the orm o compressed "as,

is converted into linear or rotary motion, dependin" on the type o actuator.

3neumatic ener"y is more desirable or main en"ine controls because it can

uic)ly respond in startin" and stoppin" as the po(er source does not need to bestored in reserve or operation. Also, pneumatic actuators are preerred in places

(here cleanliness is important, since the uid in hydraulic actuators mi"ht lea)

and contaminate the surroundin"s. =o(ever, pneumatic actuators are still li)ely

to lea), ma)in" them less ecient compared to mechanical actuators. Another

do(nside is that they ta)e up a lot o space, create a lot o noise and are dicult

to transport once installed in a place.

!i"ure @ 3neumatic actuator %source (((.marineinsi"ht.com'

The most common example is main en"ine pneumatic actuator or chan"in" o

roller position over cam shat or reversin". 0lectric actuators0lectric actuators are devices po(ered by motors that convert electrical

ener"y to mechanical torue. The electrical ener"y is used to create motion in

euipment that reuires multi5turn valves li)e "ate or "lobe valves. $ince no oil is

involved, electrical actuators are considered to be one o the cleanest and readily

available orms o actuators. 0lectric actuators are typically installed in en"ines,

(here they open and close di:erent valves. There are many desi"ns o electric

actuators and this depends on their unction in the en"ine that they are installed

in. One o its application is in electrical motor operated valve and ma"netic valve

actuator or solenoid valve.


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!i"ure 9 0lectric actuator %source (((.marineinsi"ht.com'

-echanical actuators

+t unctions throu"h convertin" rotary motion to linear motion. 7evices

such as "ears, rails, pulley, chain and others are used to help convert the motion.

$ome o the simple mechanisms used to convert motion are scre(s, (here the

rotation o the actuators nut causes the scre( shat to move in a strai"ht line,

the (heel and axle, (here the rotatin" motion o a (heel causes a belt or

somethin" similar to move in a linear motion.

.

!i"ure B -echanical actuator %source (((.marineinsi"ht.com'

2asic example o mechanical actuator is chain bloc) hoistin" (ei"ht in (hich

mechanical motion o chain over the sproc)et is utili>ed to lit a rated load.

3lun"er actuator

A typical plun"er actuator unctions somethin" li)e this a cam or plate hits

the end o the plun"er, (hich is pressed in and operates the contacts in the

s(itch. A plun"er actuator is the best choice to monitor short, controlled machine

movements, or (here space or mountin" restrictions (ill not permit the use o a

lever actuator.

!i"ure ; 3lun"er types %source ?????'


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2ut then (e are (onderin", ho( to choose an appropriate sensor? There are

some considerations that should be made. Table belo( sho( some actors that

(e should consider.

Table # 4hoosin" sensor %source ?????'2asically, a "ood sensor should have the ollo(in" characteristics

#' =i"h $ensitivity$ensitivity indicates ho( much the output o the device chan"es (ith unit

chan"e in input %uantity to be measured'.e, measure and process various chan"es

li)e chan"e in position, len"th, hei"ht, appearance and displacement that occurs

in the production sites. These sensors also play an important role in predictin"

and preventin" many uture events, thus, caterin" to the needs o many sensin"applications.

$ensors perorm a number o unctions in automated manuacturin" and

material handlin" systems. !or example, sensors can determine i an obect is

present, i toolin" is bro)en, or i product is runnin" do(n a conveyor line.

2esides, by usin" sensor and actuator, (e can reduce production cost by

replacin" human (ith that tools. And it is more e:ective and ecient (hen (e

use sensor and actuator. They "enerates similar output all the time so that head

o production should not (orry.$ensors are pervasive. They are embedded in automobiles, airplanes, cellular

telephones, radios, chemical plants, industrial plants and countless other

applications. While actuators, (e can fnd it in many plants. $uch as industrial

robot. Without the use o sensors and actuators, there (ould be no automation."ive implementation o sensor & actuator in industry %study case is allo(ed'


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One application o sensor and actuator such as in the dairy product

manuacturin". -il), cheese and ermented products, such as yo"hurt, all

reuire precise production control parameters. The cultures used in cheese and

ermented products ma)e temperature control exceedin"ly important. 3ure

cultures must be produced very careully accordin" to hy"ienic principles. A poor

or mismatched culture can lead to substantial product defcits. Ti"ht control over

stora"e times or cheese is essential. 4heese can last rom several (ee)s tomany months dependin" on temperature and humidity, both o (hich must be

monitored precisely and adapted to each brand.Whether it is mil), cream, butter, soured mil), yo"urt, and cheese, a lar"e

number o processes are reuired to "et fnished product. $tart rom mil)

reception, testin" and sortin" ra( mil) by under"oes a "entle treatment and an

eually "entle transport process, emptyin" and cleanin" mil) truc)s, recordin"

exact uantities or invoice control and production plannin", or interim ra( mil)

stora"e. Only a seamless exchan"e o data rom the laboratory system,

production, and 083 system (ill ensure the hi"hest level o product uality and

invoicin" transparency at mil) reception. Then mil) is prepared or possibleurther processin". And o course, uality is "uaranteed at every sta"e.

!i"ure D 4heese and mil) production line %source ????'

Figure 8 Delivery process of raw il! "source # $$$$%


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The primary "oal in processin" mil) is to successully process ra( mil) into

standardi>ed mil) (ith a fxed at content. The process steps ran"e rom cleanin"

and separatin" s)immed mil) and creamE throu"h settin" the at content,

pasteuri>ation, homo"eni>ation and sterili>ationE to the coolin" process. The

challen"es durin" these processes are al(ays the same 8a( mil) has to be

processed uic)ly and the process uality has to be "uaranteed.

As (e can see in f"ure F above the mil) is delivered rom the arm byusin" truc) or container. Then by usin" pipes the mil) (ill be transerred rom the

truc) to the tan). To ma)e sure that the mil) o(s in a "ood speed, o( sensor is

used there.

!i"ure !lo( sensor in delivery process %source ????'2eore come into the mil) tan)s, the ra( mil) (ill o( throu"h a cooler. +n

this step, the process pressure (ill be monitored. 3recisely monitorin" the

pressure is a decisive actor in the mil) production process. -easurin" pressure

plays an important role in mil) process. The level in the ermentation and stora"e

tan)s is oten recorded by measurin" the pressure. The various flters are also

monitored by measurin" di:erential pressures.

!i"ure #H 3ressure sensor in 8a( mil) tan) %source ????'=y"iene and cleanliness are absolutely essential or ensurin" dairy

products only contain (hat they should and this applies throu"hout the entire

production chain. The perect ans(er to this challen"e is 4leanin" in 3lace %4+3'

system automation. $ince 4+3 systems oten vary "reatly in practice, the

standard 4+3 system is a sot(are solution that supports easy creation o

individual cleanin" pro"rams, automatic implementation, and exible chan"es as

needed. With precise dosin" and capability or continuous optimi>ation, a exible

4+3 system (ill achieve optimal cleanin" and disinection (hile savin" time andminimi>in" consumption o cleanin" materials.


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8a( mil) delivery and uality5controlled handlin" is si"nifcant or every

dairy. 8a( mil) is delivered by tan)er, so the mil) has to be stored to "uarantee

continuous runnin" o the plant. Accurate level measurement is crucial in

ensurin" proper processin" and the prevention o overspill. The fllin" process to

the tan) creates turbulence and oam. The shape o the tan), the use o a"itators

and the presence o 4lean5+n53lace %4+3' euipment ma)es measurement dicult.

0arlier measurement technolo"ies (ere unreliable and tended to brea) do(ncompletely durin" cleanin"cycles that made use o caustic soda and nitric acid at very hi"h temperatures.

2esides, the mil) tan) al(ays need to provide the correct uantity o mil) (ith

the reuired characteristics. Thereore dairy5specifc unctions rom mil) tan)

instrumentation (ith temperature and level measurin" instruments are needed.

=ere is the use o temperature sensor, and hei"ht sensor.

!i"ure ## Temperature sensor in mil) tan) %source ????'

Temperature sensor6s role is to )eep the ra( mil) in the sucient

temperature so that the mil) (on6t be busu) . While the hei"ht sensor ma)e sure

that uantity o the o( in mil) is sucient.

A cost5e:ective dairy process relies on monitorin" the mil) fll level in the tan)s

precisely and continuously, and avoidin" overfllin". Ater that, the ra( mil) (ill

be o(ed into the next process (hich is pasteuri>ation.

Figure &' Pasteuri(ation process "source # $$$$%+n this process, the mil) then (ill be pumped into the pasteuri>ation place.

3recise o( meterin" is needed a"ain here. +t is not only a decisive actor or the


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mil) uality, it also helps reduce costs by ma)in" the operation o the dairy more

ecient and optimi>in" consumption. +n the pasteuri>ation process, the o(,

pressure and temperature sensor plays a "reat role. !rom pasteuri>ation process

then, (e6ll "et standardi>ed mil).

!i"ure #@ $tandardi>ed mil) stora"e %source ????'$tandardi>ed mil) (ill be o(ed a"ain into mil) stora"e. Almost the same

(ith the previous stora"e, here temperature, pressure and level or hei"ht sensor

is used. $tora"e, pumpin", and dosin". All three activities lie at the heart o ood

and bevera"e production and reuire hi"hly accurate o( measurement.

Whether it is a stra(berry in"redient added to yo"hurt or the syrup, or other

in"redients inected into mil), o( measurement is vital to uality assurance and

product consistency.*ot only that, pressure sensor plays a vital role in ood production plants.

2esides measurin" pressure or process5control purposes or or saety reasons,

pressure5measurin" instruments can be used to measure o( %orifce plate', level

%hydrostatics' and di:erential pressure %fltration and heatin" processes' to

determine parameters such as the extract content. Temperature is one o the

most important parameters o all in the ood5manuacturin" process, both rom a

saety vie(point and or process control and uality.


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Figure &) Cheese an* yoghurt anufacturing "source #$$$$%The standardi>ed mil) rom the stora"e (ill be divided into @ pipes. !or

cheese production, yo"hurt production and or bottled mil). +n the cheese and

yo"hurt production, elements used are uite complex. As (e can see rom the

picture above, temperature sensor, level sensor, pressure sensor, o( sensor,

(ei"ht sensor and identifcation sensor are used. The temperature sensor o

course used to maintain the uality o the mil). $ame role applies or the

pressure sensor. Wei"ht sensor is used to ma)e sure that the fnished cheese (ill

be standardi>ed into a specifc (ei"ht. While the identifcation sensor such as

barcode reader, is used to determine (hich (ay the cheese (ill be "oin".

Wei"hin", blendin" and dosin" actually are si"nifcantly important to the ood

and bevera"e industry. The fllin" process and the pac)a"in" o the ood products

reuire hi"hly accurate and automated systems to ensure compliance (ith the

strict uality and hy"iene re"ulations o a very competitive mar)et.While or the bottled mil) production line, temperature, pressure and

identifcation sensors are used. The standardi>ed mil) frst (ill o( into the bu:er

tan) and "oin" to other process (hich is I=T process. Temperature and pressure

sensors are used there to maintain the mil) into a certain temperature so that it

(ill ready to consumed. Ater the sensor sense the empty bottle, then actuator

(ill "rab the bottle and the mil) (ill be flled into the bottle. To control the fllin"

process, hei"ht sensor is used there. Ater puttin" bottle cap and labels then the

barcode (ill be stamped. Then pac)a"in" process (ill be"in.


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Figure &+ ,ottle* il! -nishing processThe fllin" plant and pac)a"in" department represent hi"h cost actors on

the path to ready5to5deliver dairy pac)a"in". This results rom hetero"eneous and

isolated solutions. Automation in the pac)a"in" line, by inte"rates fllin" andpac)a"in" systems in a common automation and communication standard. The

pac)a"in" standardi>ation and inte"ration o individual machines delivers cost

and ener"y savin"s throu"hout the entire production line.The use o robot (hich involves sensor to detect and actuator or

movement in pac)a"in" results in increased eciency, operational reliability, a

ocus on (or) environment and, most important o all, uniormity. All orms o

dairy product pac)a"in" can be automated. Oten, there (ill be several

operations and more than one robot bein" used in a pac)a"in" solution. This

results in a "reat number o ast5paced and precise operations bein" conducted

in a limited space. The robot6s tools can similarly be applied to several di:erentoperations such as the processin" o all types o pallets and separation sheets, as

(ell as the various )inds o pac)a"in".+nte"ration ris)s are lo(er and allo( the use o scalable production data

acuisition and evaluation systems rom optimi>ed pac)a"in" line li)e line

overvie(, dia"nostics, trac)in" and tracin", and ener"y recordin" and

mana"ement. Additionally, dairy pac)a"in" line eciency, productivity, and

availability durin" operation are all noticeably improved.

Figure &. Pac!aging/ la0eling/ pac!ing process "source # $$$1%CONC2U3ION"ive relevance bet(een intro & content

Automation improved plant perormance, (aste and ener"y minimi>ation,

product saety, and uality consistency. The trend in automation has moved a(ay

rom the consideration o individual devices or machines and to(ard a ully


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inte"rated automation solution. We are implementin" this concept consistently

(ith Totally +nte"rated Automation. The uniue and extensive ran"e o hard(are

and sot(are ensures inte"rated automation alon" the (hole production line rom

the "oods receivin" area, throu"h the processin" and production areas to the

fnished "oods (arehouse.The inte"ration is not restricted to the production process. With a uniorm

en"ineerin" environment, inte"rated and open communication as (ell asintelli"ent mana"ement systems and +T solutions, Totally +nte"rated Automation

includes all relevant areas, rom buildin" automation and ener"y mana"ement

via -0$ to maintenance and repair.

"ive related connclusion to the topic

Sensor & Actuator

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