Sensor Fundamentals


As part of the National Instruments Measurement Fundamentals Series, this set of tutorials helps you learn about a specific common measurement application topic through theory explanations and practical examples.

What You Will Learn
Essential to any data acquisition is a transducer sensor that converts real-world phenomena, such as temperature and pressure, into measurable currents and voltages. This set of tutorials is designed to provide you with essential information about using and understanding various types of sensors to acquire data.

To view the complete list of in-depth measurement tutorials, please return to the Measurement Fundamentals Main Page


Sensor Terminology

Sensor terminology 

Sensors, like other areas of technology, have a specific terminology that you must understand before you can apply them properly. Learn some of the most common terms in this tutorial.

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Measuring Temperature with Thermocouples, RTDs, or Thermistors

Thermocouples, RTDs, or Thermistors

Thermocouples are passive sensors that produce small changes in voltage with temperature. Resistance temperature sensors are active sensors whose resistance changes with temperature. Learn more about the difference between thermocouples, RTDs, and thermistors and what environments they are best suited.

View the complete guide on thermocouples, thermistors, and RTDs

Measuring Sound with Microphones


Sound waves are created by pressure variations in the air. Microphones transform sound pressure into capacitive variations, which are then converted into an electrical voltage. Review the fundamentals of sound pressure, how microphones work, and how to choose the right type of microphone. 

View the complete guide on microphones 


Measuring Strain with Strain Gages

Strain Gages

Strain gages are used to measure the deformation of a material due to an applied force. The resistance of a strain gage changes with small bends and pulls on the material. Explore basic strain concepts, how strain gages work, and how to select the right configuration type.

View the complete guide on strain gages


Measuring Pressure, Load, and Torque with Bridge-Based Sensors

 Bridge-Based Sensors

Pressure, load,a dn torque sensors measure force in different ways. Load cells measure force or weight. Pressure sensors measure force per unit area. Torque sensors measure the tendency of force to rotate an object. See how full bridge strain sensors are used to maesure pressure, load and torque. 

View the complete guide on pressure sensors

View the complete guide on load and torque sensors

Measuring Vibration with Accelerometers


Accelerometers are commonly used to measure vibration. They contain piezoelectric crystals that generate an electric charge proportional to force from oscillations of a solid. Learn about the theory of vibration, how accelerometers function, and and considerations for choosing the right accelerometer. 

View the complete guide on accelerometers