A sensor is required in every stage of product development. This article looks at the various sensors available for the purpose of test and measurement.
An electronic sensor detects and measures a physical phenomenon, such as pressure, force, temperature or acceleration, and provides a corresponding output in the form of an electronic signal like voltage, current or frequency. Depending on the application, different sensors are used for different parameters. For example, different types of pressure sensors are used to measure atmospheric pressure and pressure in the tyres of heavy vehicles.
The global marketplace for sensors is driven by innovation and development. A sensor is required in every stage of product development, including research and development (R&D), production variation control, and process monitoring and protection. Test and measurement (T&M) supports the sensing needs of those involved in development, product research, test programs, test and evaluation. Latest technologies enable the development of customised solutions for a wide range of applications. Some manufacturers also design sensors as per customer requirement and testing applications.
Typical sensors for T&M
Discussed here are some common sensors, their applications and requirements in different areas.
This type of sensor has wide applications for measuring pressure in commercial vehicles, passenger vehicles, tyre profiling, tyre contact analysis, tyre bead pressure, atmospheric pressure and heavy equipment used in agriculture, mining, forestry and construction. It minimises the effects of hysteresis and compression while designing.
To meet the most demanding T&M specifications, miniature pressure sensors are manufactured for rugged environments. Industrial processes need highly specialised pressure sensors to be used in hazardous locations.
This is the most frequently used sensor for measuring temperature in a cooling tower for thermal sensing, electric motor winding, bearings, engine oil, laboratories during different test procedures, solar applications, geo-thermal plants, rail vehicles, deep freezing technologies, health services and more.
This sensor is primarily used for detecting moving objects (especially people) and gathering data regarding position, acceleration and velocity for safety and security applications.
Speed sensor. This detects speed of an object or vehicle. It is required for speedometers, lidars, ground speed radars, pitometer logs, doppler radars, air-speed indicators and so on.
Acceleration sensor. This sensor measures the gravitational force in the direction of the sensor. It is used in mobiles, robots and aerospace applications, among others, where measuring acceleration is a major component.
Position (lidar) sensor
It measures position that can be absolute or relative. This sensor finds application in aircraft, high-speed vehicles, factory automation and security applications. The position can be linear or angular. A magnetic sensor is used for digital and linear outputs of the angle.
Micro-electro-mechanical systems (MEMS) microphone sensor
This sensor targets all audio applications where key requirements are small size, high sound quality and reliability. It has wide applications in mobile terminals, speech recognition, portable media players, laptop and notebook computers, gaming and virtual reality (VR) input devices.
It contains advanced microstructure technology to provide fast and sensitive responses to flow amount/direction of air. It is used in industrial, commercial and medical applications.
This sensor is used for measuring and recording the torque for engines, crankshafts, gearboxes, rotors and more. It converts mechanical input into electrical output. There can be static torque or dynamic torque measurement.
It measures motor vibration and helps in shock analysis for automobiles and aircraft. There can be impulse or continuous vibration measurements. This sensor measures the effect of vibration on an object under real operating conditions.
This sensor provides fast and accurate responses for power measurement. It measures the current-flowing capabilities of the device under different operating conditions.
It measures force with proportional output, along with interface pressures between two mating surfaces. It is used in the automotive industry to assist engineers with T&M, R&D and quality-control applications.
Humidity measurement is critical for the food processing industry, for the assurance of quality from production to storage and transport to final users.
This type of sensor is also used in various types of air-conditioning units. It helps in energy consumption, too.
Inertial measurement unit
These units provide motion, position and navigation sensing from a single device over six-degrees-of-freedom.
Industries served by sensors include electronic appliances, business machines, environmental testing, food and beverage, injection moulding, medical, quality assurance, package design and testing, production and process equipment, pulp and paper, and smart homes, among others. Other critical application industries are ground and flight testing, automobiles, defence and military, energy and utilities, oil and gas, mines, sub-sea communications and railways.
Map interface provides key information such as total force, peak pressure and centre of force. For better understanding of surface behaviour design validation, it is important to verify the structural integrity of lighter and cost-saving components. Other factors include research and design, quality control and manufacturing tool assist in machine setup, identifying failure modes, vendor validation, reducing downtime and FEA validation.
An automotive measurement system measures noise, vibration and harshness of component and system performance, like ride handling and drivability, road load data acquisition in electric vehicles, powertrain development and off-highway drives. Sensor technology can assist with automotive seat comfort, measuring brake pad pressure distribution, tyre tread patterns, wiper blade force profiles and more.
Pressure measurement between a human body and support surface helps assess comfort, design and ergonomics.
Nip measurement verifies uniform pressure distribution between rollers by capturing nip pressure profile data in real time and windshield wiper. To improve system performance, it is important to evaluate pressure distribution and wiper blade force profiles.
Aerospace and defence
A T&M system provides testing for ground, flight, explosives, environment, guns and their impact, underwater sensors and satellites. Specific applications can be handled by sensors equipped with software and electronics, like grip for robots, and measuring and evaluating static and dynamic pressures while grasping objects.
To sum up
A sensor mapping system consists of data-acquisition electronics, sensors and software, which run directly on a laptop or desktop PC. To upgrade a system, various sensor models and software are available. Impossible insights have been made possible through minimally-invasive force and pressure measurements.
Measurement and test sensors are electronic transducers designed for use in test equipment in R&D or for individual users. These can be permanently installed on industrial and process systems in applications such as Industrial Internet of Things (IIoT). There are measurement and pressure transmitters for flow, pressure, temperature, rotations per minute, current, voltage and other measurable factors.