Sistem Intrumentasi Industri 1

SISTEM INSTRUMENTASI INDUSTRI

Industrial Instrumentation Systems

Elita Fidiya Nugrahani

elita.nugrahani@uisi.ac.id

Departemen Manajemen Rekayasa

Universitas Internasional Semen Indonesia

Introduction

• Capaian pembelajaran: Mahasiswa prodi Manajamen Rekayasa semester 5 mampu membangun dan menganalisis sistem instrumentasi yang berfungsi sebagai monitoring, controlling , protection dengan benar

• 3 sks = 150 menit tatap muka + 180 menit tugas + 180 menit belajar mandiri dalam 1 minggu

• Prasyarat : Sistem Pengukuran dan Kalibrasi• Daftar Pustaka

• Dun, William., Fundamental of Industrial Instrumentation and Process Control, First Edition, McGraw- Hill Companies,Inc, 2005

• Bolton, Willian, Instrumentation and Control System, First Edition, Elsevier Science and Technology Books, 2004

• Bentley, J. P, Principles of Measurement System– 4th edition, Pearson Prentice-Hall, 2005.

• Bela G. Liptak., Kriszta Venczel., Instrument Engineers' Handbook, Fourth Edition, Volume One: Process Measurement and Analysis

Contents

UAS (35%) 25

UTS (20%)

1. Dasar sistem instrumentasi dan perkembangannya 2. Elemen dan diagram blok pengukuran (5%)3. Process Flow Diagram (PFD) dan Piping and Instrumented Diagram (P&ID)4. Konsep Sistem Instrumen sebagai measurement : sensing, signal conditioning,

signal processing, display (15%) (10%)5. Basic Process Control System (BPCS) 6. Safety Instrument System (15%) (10%)

7. Jenis-jenis sistem pengendalian di industri8. Mode kontroler: sequential (On-Off - PLC), kontinyu (PID & FLC), dan DCS

(Distributed Control System). (5%)9. Pemodelan sistem (10%)10. Analisa kestabilan metode Routh Hurwitz dan tuning PID dari suatu sistem

(15%)

1. The General and Development of Instrumentation Systems

1.1 Definition

System

Instrumentation

Instrumentation Systems

an arrangement of parts within some boundary which work together to provide some form of output from a specified input or inputs.

basis for process control in industry including measuring, controlling, and protecting function.

measuring, controlling, and protecting numerical value corresponding to the variable being measured.

1.2 Timeline of Instrumentation Systems

1.2.1 Manual Control

1.2.2 Pneumatic and Hydraulic Control

1.2.3 Automatic Control

1.3 Block Diagram of Measurement Systems

1.4 Block Diagram of Open Loop Control Systems

Input reference Controller Plant Output

• Also called a non-feedback controller, is a type of controller that computes its input into a system using only input reference and its model of the system.

• Not use feedback to determine if its output has achieved the desired goal of the input

• Example : Flare control system on stove

flarePressureRegulator

Pin Ps

Valve input

1.4.1 Definition of Open Loop Control Systems

1. Open loop systems are inaccurate and unreliable

2. The changes in the outputs due to external disturbance are not corrected automatically

1.4.2 Advantage and Disadvantage of Open Loop Control Systems

1. Open loop system is simple and economical

2. Construction of open loop system is easier

3. Open loop systems are generally stable

Advantage

Disadvantage

1.5 Block Diagram of Close Loop Control Systems

• A system where the actual behavior of the system is sensed and then fed back to the controller and mixed with the reference or desired state of the system to adjust the system to its desired state.

• The objective of the control system is to calculate solutions for the proper corrective action to the system

• Example :

1.5.1 Definition of Closed Loop Control Systems

1. Closed loop control systems are costlier and complex

2. The feedback in the closed loop system may lead to oscillatory response

3. The feedback reduces the overall gain of the system

4. Stability is the major problem in the closed loop system and more care is needed to design a stable closed loop system

1.5.2 Advantage and Disadvantage of Closed Loop Control Systems

1. Closed loop control systems are more accurate even in the presence of non-linearities

2. The sensitivity of the system may be made small to make the system more stable

3. The closed loop systems are less affected by noise.

Advantage

Disadvantage

PLANT

ACTUATOR

CONTROLLER

SENSOR

1.6 Component of Control Systems

• Certain components that work to achieve its purpose.• Example: Continuous Stirred-Tank Reactor (CSTR)

Mixer

Flow input

(Tin ,w)

Flow output

( Tout )Q – Heater

1.6.1 Plant

• SensorDevice that responds to a physical stimulus (as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (a signal relating to the quantity being measured).

• Example:• Thermocouple where millivolt depends on temperature• Strain gauge where resistance depends on mechanical strain• Orifice plate where pressure drop depends on flow rate.

1.6.2 Sensor

Example• Potentiometer: displacement sensor that converts linier

displacement to resistance.

Rt

R1

V out V in

Level Sensor: buoy connected to secunder measurement system (potentiometer)

inT

out VR

RV .1

• Kontroler merupakan salah satu komponen dalam sistem pengaturan yang memegang peranan sangat penting.

• Kontroler menghasilkan sinyal kontrol sedemikian hingga plant memberikan respon sesuai dengan spesifikasi performansi yang diinginkan.

• Example: on-off, PID, fuzzy logic

1.6.3 Controller

• Type of motor that is responsible for moving or controlling a mechanism or system.

• Most of control signal doesn’t have enough power to drive plant.• operated by a source of energy, typically electric current, hydraulic fluid

pressure, or pneumatic pressure, and converts that energy into motion.

R(s)

Sensor / Tranduser

Kontroler

Plant +

-

Aktuator C(s)

C*(s)

E(s)

1.6.4 Actuator

Electrical Actuator

Selenoid• Changed electric signal to mechanical movement.• coil dan plunger

Mechanical Actuator

Motor DC • Changed voltage to mechanic rotary

La Ra

ia

ea J T

ω,θ

if

B

• Classification:

1. Input

2. OutputInput Plant /

ProcessOutput

• Other classification:1. Manipulated variable (u)2. Controlled variable (y)3. Exogenous variable (d)

1.6.4 Variable

Plant /Process

du

y

• Variable in Continuous Stirred-Tank Reactor (CSTR)

1. Input : Tin , w , Q

2. Output : Tout

CSTR ToutTin , w , Q

Mixer

Flow input

(Tin ,w)

Flow output

( Tout )Q – Heater

controller Control valve Cstr/mixing tank

PH transmitter

e

Overview