About this previous year paper
SENSOR & INSTRUMENTATION – Full Paper
TIME: 3 Hours | MAX MARKS: 70
This examination evaluates a student’s understanding of sensors, transducers, measurement systems, data acquisition, smart instrumentation, and modern embedded measurement technologies. The paper includes conceptual questions, applied explanations, block diagrams, and analytical reasoning related to sensing principles used in engineering systems.
The question paper is divided into three major sections to test knowledge clarity, analytical skills, and system-level interpretation.
SECTION A – Short Conceptual Questions (14 Marks)
This section contains seven brief questions, each designed to check the student’s basic understanding of fundamental sensor and instrumentation concepts.
Key Concepts Covered
• Transducers
Understanding devices that convert physical quantities (force, temperature, pressure, displacement) into electrical signals.
• Types of Displacement Sensors
Knowledge of resistive, capacitive, inductive or optical-based displacement sensing techniques.
• Thermal Imaging
Use of infrared radiation detection for temperature distribution analysis, industrial diagnostics, medical imaging, and surveillance.
• Proximity Sensors
Capacitive, inductive, ultrasonic, or optical sensors used to detect object presence without physical contact.
• Programming Loops
Understanding For, While, Sequence loops used in automation, embedded systems, and virtual instrumentation.
• ADC (Analog-to-Digital Converter)
Its role in converting analog sensor output into digital data for controllers and processors.
• Self-Calibration
How smart sensors auto-adjust to improve accuracy, correct drift, and maintain reliability without manual recalibration.
This section measures clarity, accuracy, and concept-level understanding.
SECTION B – Applied & Analytical Questions (21 Marks)
Students must attempt any three questions. These require explanatory diagrams, working principles, and application-based reasoning.
Topics Included
• Potentiometer as a Displacement Sensor
Explaining resistive track movement, linear/angular displacement detection, and common industrial uses.
• Thermistor Functioning & Use
Temperature-dependent resistance variation, negative temperature coefficient behavior, and thermal sensing applications.
• Graphical Programming Structures
Case selectors, Sequence frames, Formula nodes used in LabVIEW or graphical system design.
• Data Acquisition System Block Diagram
Signal conditioning → ADC → Controller → Memory/Output stages.
• Intelligent Sensors
Integration of sensing element + signal processor + microcontroller + communication interface.
This section evaluates understanding, analysis, and the ability to explain sensing systems logically.
SECTION C – Long Descriptive Questions (21 Marks)
Students must attempt one question from each subsection (3–7). These questions involve in-depth explanations, working mechanisms, and diagram-supported reasoning.
C1: Mechanical / Electrical Sensors
Option A – Strain Gauge Working
Explaining resistance change due to strain, Wheatstone bridge interface, and force measurement applications.
Option B – Diaphragm-based LVDT for Pressure
Pressure deflection of diaphragm → displacement of LVDT core → converted into voltage.
C2: Position & Flow Measurement
Option A – Hall Effect Sensor for Position
Magnetic field interaction generating voltage proportional to position or rotation.
Option B – Ultrasonic & Laser Flow Sensors
Time-of-flight principle (ultrasonic) and Doppler/beam interruption methods (laser-based flow).
C3: Virtual vs Traditional Instrumentation
Option A – Virtual Instrumentation
Software-based measurement systems, flexibility, data logging, remote access, and cost advantages.
Option B – Comparison with Traditional Instruments
Hardware-only instruments vs PC-based, reconfigurable measurement systems.
C4: DAC Systems & Communication
Option A – R-2R Ladder DAC
Binary-weighted resistor network, equal resistance ratios, stability, and advantages over weighted resistor DAC.
Option B – Data Sockets
Network communication objects enabling real-time data exchange, remote monitoring, and distributed measurement systems.
C5: Smart Sensor Characteristics & Components
Option A – Components of a Smart Sensor
Sensing element, ADC, microcontroller, memory, calibration module, communication interface.
Option B – Characteristics of Smart Sensors
Self-calibration, self-testing, self-communication, diagnostics, and automatic error reporting.
Purpose of the Examination
The BOE305 Sensor & Instrumentation exam ensures that students can:
Understand fundamental sensing principles
Explain the working and application of major sensors
Interpret block diagrams and signal flow
Analyze temperature, displacement, pressure, and flow measurement systems
Use concepts of data acquisition and virtual instrumentation
Understand smart sensors and modern embedded measurement technologies
Solve real-world engineering measurement problems
The paper bridges classical measurement techniques with modern intelligent sensing technologies.