CHEMICAL SENSORS

INTRODUCTION

• A chemical sensor is a device that transforms chemical information, ranging from the concentration of a specific sample component to total composition analysis, into an analytically useful signal.

PARTS OF CHEMICAL SENSORS

• Chemical sensors contain two basic functional units: i) receptor part ii) transducer part.

PARTS OF SENSORS

Classification

• Direct output sensors
• Indirect output sensors
• Direct sensor: The chemical reaction or the presence of a chemical produces a measured electrical output
• Indirect output sensors: Indirect (also called complex) sensor relies on a secondary, indirect reading of the sensed stimulus.

LIST OF CHEMICAL SENSOR

• Oxygen sensors
• PH glass electrode
• Carbon di oxide sensors
• Catalytic bead sensors
• Holographic sensors
• Nitrogen oxide sensors

oxygen sensor

Oxygen sensor is a
device that measures
the proportion of O2
in the gas or liquid being
analysed
Automotive computer
systems use a sensor in
the exhaust system to measure the oxygen content of the exhaust.

The inner and outer surfaces of the thimble are plated with platinum.

The inner surface becomes a negative electrode; the outer surface is a positive electrode

BASIC TYPES:

• There are three basic types of oxygen sensors. They are the:
• Zirconia
• Titania
• Air Fuel

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