Sensor Fundamentals

What are Sensors?


Essential to any data acquisition application is a transducer sensor that converts real-world phenomena, such as temperature and pressure, into measurable currents and voltages. Let’s explore the types of things you want to measure and map them to the types of sensors you need to get there. Before we get started, you can also review sensor terminology such as sensitivity, range, precision, resolution, and more. Explore the following sections to learn about the types of sensors used for each measurement type.


Types of Sensors



Microphone Sensor with a Sound and Vibration Input Module and CompactDAQ Chassis

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.


Load Cell with a Strain/Bridge Input Module and CompactDAQ Chassis

Strain gauges are used to measure the deformation of a material due to an applied force. The resistance of a strain gauge 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.


Pressure Sensor with a Voltage Input Module and CompactDAQ Chassis

Pressure is defined as force per unit area that a fluid exerts on its surroundings. The three most universal types of pressure transducers are the bridge (strain-gage based), variable capacitance, and piezoelectric. Explore basic pressure concepts and how different pressure sensors work.


 Load Cell with a Strain/Bridge Module and CompactDAQ Chassis

Load is a term frequently used to refer to the force exerted on a structure or body measured in Newtons (N). Explore the fundamentals of load and how different load cell specifications affect performance.


 Torque sensor with NI CompactDAQ

Torque is the tendency of a force to rotate an object about an axis. Explore the fundamentals of torque and how different torque sensor specifications affect performance.


Thermocouple with a Temperature Input Module and CompactDAQ Chassis

Thermocouples produce small changes in voltage in relation to temperature while resistance temperature sensors have resistance changes in relation to temperature. Learn more about the difference between thermocouples, RTDs, and thermistors and the environments that best suit them.


Accelerometer with a Sound and Vibration Input Module and CompactDAQ Chassis

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


Battery with NI CompactDAQ

While voltage measurements are the simplest of the different types of analog measurements, they can present unique challenges. Examine general DC voltage measurements that do not involve an intermediary sensor setup.