Applied Sensor Technology

Outline Introduction Examples of Sensors Basic readout electronics Semiconductor detectors

Introduction A sensor measure various physical parameters –Motion –Height, weight and volume –Pressure, Tensile stress –Temperature –Flow –Irradiation –Energy –………

Introduction Why do we need sensors?

Introduction Elements of a measurement system

Introduction

Sensor Characteristics –Accuracy –Calibration –Dead-zone –Drift –Error –Hysteresis –Lag –Linearity –Operating life –Precision Sensor Characteristics –Range –Rating –Reliability –Repeatability –Reproducibility –Response –Resolution –Sensitivity –Stability –Static error –Tolerance

Introduction

Examples of Sensors Resistance Strain Gauge –Measure change in size of a solid object, due to the object being strained.

Examples of Sensors Measuring volume in a fuel tank 1 2

Examples of Sensors Piezoelectric pressure sensor –Mechanical pressure –Gas pressure

Examples of Sensors Audio (change in air pressure) –Recording –Mixing (Signal processing)

Examples of Sensors Temperature measurement, thermocouple element

Examples of Sensors Temperature measurement by heat radiation

Basic readout electronics Purpose –Amplify small signal from the sensor –Signal processing to suppress noise

Basic readout electronics Operational amplifier –Voltage Comparator –Voltage amplifier Inverting Non-inverting

Basic readout electronics Operational amplifier –Differential amplifier –Instrumentation amplifier

Basic readout electronics Operational amplifier –Voltage amplifier –Current amplifier –Charge sensitive amp.

Semiconductor detectors

SiO 2 Al L n-type Si substrate P+P+ n+n+ hv eh i1i1 i2i2 0 XcXc Low non linearity ~0.1% Independent of light spot focus Simple calculation of the position Lateral photoeffect PSD

Applied Sensor Technology Semiconductor physics Semiconductor processing Analog Electronics