A Strain Gauge Based Torque Transducer (Sensor) …

1 A Strain Gauge for Measuring 1 Faculty of Science, University of Sirte2 Faculty Abstract- Torque measurement is paramount in engine and transmission testing, turbine testing, pump testing and testing of gear trains and power measurement within propulsion systems. Monitoring Torque can be critical to the performance of axles, drive trains, gear drives, and electric and hydraulic motors. Other in-plant applications include gas and steam turbines. Really, Torque is an important factor in anything that rotates or spins on a shaft, spindle or axle. In this research, the shaft wfor the application of a V shaped Strain Gauge ; Torque on a rotating shaft. The implementation of the Transducer will be executed. This paper also discussestransducer with Spider8 measurement electronics, diagram of the measuring chain, main points of the measuring software and the measurement accuracy.

2 Ttested with simulated loads. The structure possible for measuring Torque with Strain gauges on it. This saves wear on the drive system and increases product quality. I. INTRODUCTIONA lthough Torque is unquestionably an important mechanical quantity in the construction of machines; its significance is not confined to that area alone. The precise measurement of Torque , particularly in rotating components, places heavy demands on manufacturers and users of test benches. The situation is further complicated by the trend towards improvmechanical performance of modern engines by increasing the rotational speed; coupled with a desire for greater accuracy in such areas as the measurement of efficiency [2].There is no denying that signals play a major role in our life. A signal can be a function of time, distance, position, temperature, pressure, Torque , etc.

3 , and it represents some variables of interest associated with a system. For examplean electrical system the associated signals are electric cuand voltage. In a mechanical system, the associated signals may be force, speed, Torque , etc [1].[4]. It isthat the most important quantity of a rotating machine is the acting mechanical power. There are many methods to measure this. By definition, the most straightforwardby measuring both the Torque directly on the rotating shaft and the rotational speed. There are many widely used measuring methods and more or less standardized instruments for measuring rotational speed; howevermeasurement device is specific for each application, sincemust be built onto the machine s structure. Based Torque Transducer (Sensor) Measuring Dynamical Load Hilal Muftah1 and S. M. Haris2 Faculty of Science, University of Sirte, Sirte, Libya aculty of Engineering & Built Environment Universiti Kebangsaan Malaysia 43600 UKM Bangi, Malaysia Torque measurement is paramount in engine and transmission testing, turbine testing, pump testing and testing of gear trains and power measurement within propulsion systems.

4 Monitoring Torque can be critical to the performance of axles, drives, and electric and hydraulic motors. Other plant applications include gas and steam turbines. Really, Torque is an important factor in anything that rotates or spins on the shaft will be adapted Strain Gauge ; to measure the implementation of the Transducer is paper also discusses calibration of the Transducer with Spider8 measurement electronics, the block the measuring chain, main points of the measuring The Transducer is then of a grinder makes it possible for measuring Torque with Strain gauges on it. This saves product quality. NTRODUCTION ough Torque is unquestionably an important mechanical ; its significance is not confined to that area alone. The precise measurement of Torque , particularly in rotating components, places heavy demands on benches.

5 The situation is further complicated by the trend towards improving the dern engines by increasing the with a desire for greater accuracy in such areas as the measurement of efficiency [2]. ignals play a major role in our life. can be a function of time, distance, position, ., and it represents some of interest associated with a system. For examples, in an electrical system the associated signals are electric current echanical system, the associated signals It is undoubtedly true rotating machine is the acting mechanical power. There are many methods to measure straightforward method would be the Torque directly on the rotating shaft and the rotational speed. There are many widely used measuring methods and more or less standardized instruments for however for Torque , the device is specific for each application, since it nto the machine s structure.

6 For many years metallic resistance Strain gauges have been used as principal sensors for measuring Torque on a shaft. Therefore, Gauge Torque Transducer is capa[3].[5]. Torque is defined as a measure object that causes it to rotate. about an axis, which is call Distance (r) from the pivot point to the point where the force acts is called the moment arm. Note that a vector, and points from the axis of rotation to the point where the force acts, as shown in [1] More generally, the torqu Position (r) in some reference frame) can be defined as the cross product: Where particle's position (r)fulcrum, and Force (F) is the Magnitude ( ) of the Torque is given by Where Distance (r) is the distanceto the particle, Force (F) applied, and Angle ( ) is the angle betweenforce vectors [16].[17].[18]. II. MATERIALS AND A.

7 Strain Measurement CStrain gauges change resistance in response to the surface strains that they sense. The relationship between Strain and Torque Transducer (Sensor) .Rotation metallic resistance Strain gauges have been used as principal sensors for measuring Torque on a shaft. Therefore, the Strain e Torque Transducer is capable to measure dynamical loads measure of the force acting on an to rotate. Force (F) rotates the object called the Pivot Point (O) . The from the pivot point to the point where the force acts is called the moment arm. Note that Distance (r) , is also a vector, and points from the axis of rotation to the point where the force acts, as shown in [1].[7].[8].. Definitions More generally, the Torque on a particle (located at in some reference frame) can be defined as (1) ) is the vector relative to the is the force acting on the particle.

8 The of the Torque is given by (2) distance from the axis of rotation ) is the magnitude of the force the angle between the position and ATERIALS AND METHODS Strain Measurement Circuit ges change resistance in response to the surface they sense. The relationship between Strain and Development, Energy, Environment, EconomicsISBN: 978-960-474-253-075 resistance is expressed by the Gauge factor ( ) of the Strain gage foil, which can range from ( . )foil material is constantan, (a 55% copper alloy) having a Gauge factor of ( ). The are converted into voltage changes by passiveThe voltage is then amplified for signal transmission or display[11].[18].[20]. Excitation is usually supplied to such networks regulated power supply. The output of networks used with semiconductor Strain gauges may be large enough, for some applications to obviate the need for amplification [2] Wheatstone bridge circuits are used for most types of Strain measurements.

9 The Wheatstone bridge is well suited for measurement of small changes in resistance and issuitable for measuring resistance change(SG). It is commonly known that the Strain gaapplied Strain into a proportional change of resistance. The applied strains is defined by Where ( ) is the change in length and (l) is the original relative change of the resistance of a Strain gadescribed by the equation Where ( ) is the change in resistance and resistance. The "factor (k)", also known as the gacharacteristic of the Strain Gauge obtainedThe exact value is specified by the Strain gaIn general, the Gauge factor for metal Strain gages is about the following, the Wheatstone bridge circuit described with respect to its application in Strain gaapplications.

10 Two different presentations are is Based on the original notation of Wheatstone, and is an alternate notation that can be more easily understoodperson without an electrical or electronic engineeringbackground. Both versions are, in fact, identical in their electrical functions. Wheatstone bridge circuit The most common Wheatstone bridge circuit used as a Strain Gauge bridge is the four arm bridge constructionwhich each of the four arms is active, which means that each arm contains a Gauge that senses Strain [2]. B. Design of the Torque Transducer with Strain G ge factor ( ) of the Strain ). The most common a 55% copper and 45% nickel changes in resistance are converted into voltage changes by passive circuit networks. The voltage is then amplified for signal transmission or display supplied to such networks by a regulated power supply.