Basic Elements of an Electronic Instrument

An electronic instrument is made up of the following key elements:

• Transducer
• Signal modifier
• Indicating device

Transducer

This is the first sensing element and is needed only when measuring a non-electrical quantity such as pressure or temperature. Its task is to convert the non-electrical physical quantity into an electrical signal. An example of a transducer is a thermocouple for sensing temperature and converting it into an electrical signal.

If the quantity being measured is already in electrical form, then we don’t need the transducer.

Signal Modifier

This is second element and its role is to make the incoming signal appropriate for application to the indicating device. For instance, the signal may require amplification before it can be properly displayed. Other types of signal modifiers are:

• Voltage dividers for reducing the amount of signal applied to the indicating device.
• Wave shaping circuits such as filter, rectifier or chopper, etc.

Indicating Device

This final element function is to display the signal. The indicating device may be a deflection type meter or be in a digital readout.

You may also read:

• Passive vs. Active Sensors
• Types of Sensors used in Measurement and Process Control
• Performance Characteristics of Digital Measurement Instruments
• Key Instruments Used By Electronics Engineers