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Force and weight relationship The weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity, w = m*g. Since the weight is a force, its SI unit is the newton. For an object in free fall, so that gravity is the only force acting on it, then the expression for weight follows from Newton's second law. Force measurement using a load cell A Load cell is a force transducer intended for weight measurement that generates an electrical signal whose magnitude is directly proportional to the force being measured. Commonly types of load cells There are four common types of load cells.   Pneumatic  Hydraulic Capacitive Strain gauge  Pneumatic load cells:  Let us now understand how a pneumatic load cell works. Since it is a pneumatic load cell, we know that it will deal with air pressure. Construction:  A pneumatic load cell consists of an  elastic diaphragm attached to a platform surface where the weight will be pla

What is a force? In science, force is the push or pull on an object with mass that causes it to change velocity (to accelerate). Force is represented as a vector, which means it has both magnitude and direction. According to Newtons 2nd law of motion F = m·a Where F = force, m = mass, and a = acceleration Force measurement The most popular method for measuring force is using a strain gauge. We measure the strain developed due to force using strain gauges; and by multiplying the strain with the effective cross-sectional area and Young’s modulus of the material, we can obtain force.  Load cells and Proving rings are two common methods for force measurement using strain gauges.  We will first discuss the principle of strain gauge and then go for the force measuring techniques. Let us now understand what is the strain? What is the strain? The strain is the amount of deformation of a body due to an applied force. More specifically, strain (e) is defined as the fractional change in length. S

Displacement, Position and Proximity Sensors Resistive Element or Potentiometer Capacitive Elements Strain Gauged Element Inductive Proximity Sensors Eddy Current Proximity Sensors Differential Transformers Optical Encoders Hall Effect Sensors Pneumatic Sensors Proximity Switches Rotary Encoders Temperature Sensors Thermistors Thermocouple Bimetallic Strips Resistance Temperature Detectors Thermostat Light Sensors Photo Diode Phototransistor Light Dependent Resistor Velocity and Motion Pyroelectric Sensors Tach generator Encoders (rotary and linear) Fluid Pressure Diaphragm Pressure Gauge Tactile Sensor Piezoelectric Sensors Capsules, Bellows, Pressure Tubes Liquid Flow and Level Turbine Meter Orifice Plate and Venturi Tube Differential Pressure Transmitter (DPT) IR Sensor Infrared Transmitter and Receiver Pair Force Strain Gauge Load Cell Cantilever beam Touch Sensors Resistive Touch Sensor Capacitive Touch Sensors UV Sensors Ultraviolet Light Detector Photo Stability Sensors UV Photo

  Classification of Sensors The scheme of classifying sensors can range from very simple to very complex. The stimulus that is being sensed is an important factor in this classification. Some of the stimuli are Acoustic: Wave, spectrum, and wave velocity. Electric: Current, charge, potential, electric field, permittivity, and conductivity. Magnetic: Magnetic field, magnetic flux, and permeability. Thermal: Temperature, specific heat and thermal conductivity. Mechanical: Position, acceleration, force, pressure, stress, strain, mass, density, momentum, torque, shape, orientation, roughness, stiffness, compliance, crystallinity, and structural. Optical: Wave, wave velocity, refractive index, reflectivity, absorption, and emissivity. The sensors’ conversion phenomenon is also an important factor in the classification of sensors. Some of the conversion phenomena are  magnetoelectric,  thermoelectric  photoelectric.