China
Africa
Explore chapters and articles related to this topic
Force
Published in Martin Novák, Introduction to Sensors for Electrical and Mechanical Engineers, 2020
Strain gauges can be installed either directly on the measured object or on a load cell. Load cells are used, for example, in weighting applications. The load cell is being deformed with the applied external force. An example of a strain gauge placed on a composite material is shown in figure 5.17. A beam-type load cell is shown in figure 5.19; an S-type load cell is shown in figure 5.19. A strain-gauge rosette used for residual stress measurement is shown in figure 5.20. A beam load cell in weighting application is shown in figure 5.21. The principle of an S-type load cell is shown in figure 5.22, the load cell itself is then shown in figure 5.23, where it was used on a torque dynamometer.
Thermal, mechanical, quantum, and analytical sensors
Published in Patrick H. Garrett, High Performance Instrumentation and Automation, 2018
A load cell is a transducer with an output proportional to an applied force. Strain gauge transducers provide a change in resistance due to mechanical strain produced by a force member. Strain gauges may be based on a thin metal wire, foil, thin films, or semiconductor elements. Adhesive-bonded gauges are the most widely used, with a typical resistive strain element of 350 Ω that will register full-scale changes to 15 Ω. With a Wheatstone bridge circuit, a 2-V excitation may therefore provide up to a 50-mV output signal change, as described in Figure 1.10. Semiconductor strain gauges offer high sensitivity at low strain levels with outputs of 200 to 400 mV. Miniature tactile force sensors can also be fabricated from scaled-down versions of classic transducers employing MEMS (micro-electro-mechanical system) technology. A multiplexed array of these sensors can provide sense feedback for robotic part manipulation and teleoperator actuators.
Auxiliary Hydraulic Variables
Published in Jochen Aberle, Colin D. Rennie, David M. Admiraal, Marian Muste, Experimental Hydraulics: Methods, Instrumentation, Data Processing and Management, 2017
Jochen Aberle, Colin D. Rennie, David M. Admiraal, Marian Muste
Strain-gauge based load cells can be built with different sensitivities, as many different strain-gauges are commercially available. Load cells may be designed as “bending-type load cells”, “shear-type load cells”, and “tension and compression load cells”, i.e., by measuring the strain of a deforming body caused by bending, shear, or tensile stress, respectively (see Hufnagel & Schewe, 2007 for details). Each of these load cell types can be constructed as a single load cell, enabling the determination of single force components. A combination of these individual components enables the measurement of forces and torques in multiple directions. Sensors should be selected such that the hydraulic load causes a sufficiently large deformation of the load cell. This requirement can be problematic for the measurement of small forces.
Evaluation of Accuracy of an Indigenous Cost-Effective and User-Friendly Alarm System for Monitoring of Intravenous Infusion- IV ALERT
Published in IETE Journal of Research, 2023
Goverdhan Dutt Puri, Tanvir Samra, Arvind Jindal, Harshit Singla, Sushant Konar
Load cells are a type of force transducer; converting force exerted on the load cell to a measurable electrical signal. The strength of the signal changes in proportion to the force applied. Factors affecting the system’s weighing accuracy are [15] as follows: Load cell accuracyLoad factors: The cells alone must support all the weight to be measuredEnvironmental forces – wind loading, shock loading, vibration, large temperature changes, and pressure differentials, can produce errors in the load cell signal.Interference with signal transmission: It is equally important to ensure that the weight controller measures only the load cell electrical signal. Radio frequency interference (RFI), electromechanical interference (EMI), moisture, and temperature can all interfere with this electrical signal.
Review of Candidate Techniques for Material Accountancy Measurements in Electrochemical Separations Facilities
Published in Nuclear Technology, 2020
Jamie B. Coble, Steven E. Skutnik, S. Nathan Gilliam, Michael P. Cooper
Load cell measurements use an electrical signal to proportionally measure the magnitude of an applied force such as a compressive force.105 Similar to the level and density measurements, no quantification of material composition or concentration is obtained from load cell measurements alone. Rather, load cell measurements indicate the overall mass moving through the system, which may be useful to detect some postulated diversion scenarios. This type of measurement can be applied at almost every area within the pyroprocessing facility, including the electrorefiner, the processing units, the drawdown, and input and output accountancy. The uncertainty associated with load cell is roughly 0.05% but can increase due to hardware issues, such as incorrect mounting or equipment damage.13
Theoretical and Experimental Investigation of Subcooled Flashing Flow through Simulated Steam Generator Tube Cracks
Published in Heat Transfer Engineering, 2019
Ram Anand Vadlamani, Shripad T. Revankar, Jovica R. Riznic
A 25.4-cm bolted bonnet full port gate valve initiates the experiment and the steam produced in the test section break is piped to the weigh tank where it is condensed. This allows for the dynamic measurement of the mass of water in the weight tank. The following describes the components involved in this measurement. A 189.3-liter condensing tank is suspended from two high-precision miniature load cells via steel cable at LC1 and LC2. The load cells work in both tension and compression and have a load capacity of 136.07 kg each. Both were manufacturer-calibrated and in-house calibrated. Their full scale output is different for each, but is approximately 2.2 mV/V with a combined error of less than 0.1%. Over a 20-minute period their full scale creep is less than 0.05%. In order to increase the accuracy of the load cell data acquisition, a signal amplifier is used to amplify the signal before being recorded. All electronic components are allowed to warm up a sufficient amount of time before an experiment was conducted.