When activated, the torque shaft rotates, causing the cutting element to excise diseased plaque from the artery. The deflecting torque can be produced by utilising any of the effects mentioned earlier. Manufacturers warranty operating instructions stahlwille torque wrench pages 1. Different types of torque wrench pt hyprowira adhitama. Thus the deflecting system of an instrument converts the electric current or potential into a mechanical force called. We have already seen that the moving system of the instrument will tend to move under the action of the deflecting torque. Deflecting torquethe deflecting torque is produced by making one of the magnetic, heating, chemical, electrostatic and electromagnetic induction effect of current or voltage and cause the moving system of the instrument to move from its zero position. Measurements and instrumentation 2 mark questions answers pdf.
Measuring instruments classification deflecting, control and damping torques ammeters and voltmeters pmmc, moving iron type instruments expression for the deflecting torque and control torque errors and compensations, extension of range using shunts and series resistance. Measurements and instrumentation questions and answers pdf free download for ece mcqs objective type interview questions lab viva manual gate cat syllabus. All deflecting beam torque wrenches are constructed from chrome plated alloy steel and conform to ansiasme b107. The transducer generates measured signals during the calibration. The method of producing this torque depends upon the type of instrument. A torsion bar is a straight bar of metal or rubber that is subjected to twisting shear stress. In a moving iron meter, the deflecting torque is proportional to a. The deflecting element 15a is adapted to be mounted within a centrifugal separator in a manner and position similar to that shown in fig. Us3517821a deflecting element for centrifugal separators. Conversely, with the increase in stabilizer diameter, the deflecting force on the drill bit decreases. Seekonk deflecting beam torque wrenches are designed with pivoting handles that direct torque force through a fixed point for more accurate performance. This helps in keeping the pointer at a fixed position after initial deflection.
Download practical maritime ebooks with amazing bonuses. Iso9001certified a2la accredited to iso17025 engineering fundamentals of threaded fastener design and analysis. On the deflecting beam torque wrench shown in figure 82, the deflecting element is the beam itself. Moving iron instruments principle, operation and type, theory of.
Torque in indicating instrument deflecting, controlling. If deflecting torque were acting alone, the pointer would continue to move indefinitely. With a powerful magnet, its torque to weight ratio is very high. The action of the deflecting torque for moving system containing pointer is shown in fig. Land rover workshop manuals discovery ii torque wrench. Sufficient steerability can be achieved by reinforcing the catheter shaft with braided wire to enhance torque transmission and provide kink resistance. Electrostatic voltmeters electrometer type and attracted disc type extension of range of e.
The galvanometer which is used for estimating the quantity of charge flow through it is called the ballistic galvanometer. This weight produces a controlling torque due to gravity. A calibration tool for a torque wrench includes a measuring head and a deflecting lever. Ways to obtain deflecting torques a magnetic field effect b electric field effect c electromagnetic field of attraction or repulsion d electromagnetic induction effect e heating effect or thermal effect f chemical effect g hall effect hpiezo electric effect 4. Measurement is an act or the result of comparison between the quantity and a predefined standard. Let us derive an expression for deflecting torque for this power factor meter. Deflecting definition of deflecting by the free dictionary. Power factor meters electrodynamometer type power factor. This needle will move towards certain numbers or scales, where this movement is based on the magnitude of the tightening moment performed. Commonly used instruments in power system measurement are a induction b moving coil or iron c rectifier d electrostatic ans. Permanent magnet moving coil instrument pmmc working and. Hence there exists a necessity to control the movement of the pointer such that it comes to rest at the deflected position.
Electrical measurements pdf notes em pdf notes smartzworld. In movingiron instruments the movable system consists of one or more pieces of speciallyshaped soft iron, which are so pivoted as to be acted upon by. But on account of the control torque, it will try to occupy a position of rest when the two torques are equal and opposite. The action of the deflecting torque for moving system containing. An instruments moment, resulting from the quantity measured, that acts to cause the. Controlling torque increases with the deflection of the moving system so that the final position of the pointer on the scale will be. Electrostatic voltmeterselectrometer type and attracted disc type extension of range of e. Mechanically the lift transducer consists of an arm, quill shaft, worm wheel, worm gear and a torque limiter as shown in fig. Classification deflecting, control and damping torques ammeters and voltmeters pmmc, moving iron type instruments expression for the deflecting torque and control torque errors and compensations, extension of range using shunts and series resistance.
Moving iron instruments principle, operation and type. Advantages of pmmc the various advantages of pmmc instruments are, it has uniform scale. The deflecting torque is produced by making use of one of the magnetic, heating, chemical electrostatic and electromagnetic induction effects of current or voltage and causes the moving system of the instrument to move from its zero position when the instrument is connected in an. In the above figure an ammeter having full scale value of 2 ampere current in the above figure current is one ampere.
A torsion spring is a spring that works by twisting its end along its axis. Deflecting torque is the amount of torque needed for the pointer to move from its zero position. The controlling torque is provided by two phosphor bronze hair. The controlling torque produced is mainly due to ribon suspension. The controlling torque t c opposes the deflecting torque and increases with the deflection of the moving system. When it is twisted, it exerts a torque in the opposite direction, proportional to the amount angle it is twisted. The pointer comes to rest at a position where the two opposing torques are equal i.
The deflecting torque or operating force is required for moving the pointer from its zero position. Eec 126 instrumentation 1theory measuring instrument. The phoenix atherectomy deflecting cathete r is a long, flexible catheter with an outer deflecting shaft and an inner shaft that contains a torque shaft which is attached to a metal cutting element at the distal catheter tip. The measuring head has a transducer configured to have a head portion of the torque wrench coupled thereto. A pointer attached to the socket end remains straight and indicates the applied load as torque on a graduated plate attached to the handle end.
Secondary instruments, deflecting torque, controlling. This is about the deflecting torque or forces in electrical indicating instruments and deflecting system in indicating. In the drawings illustrating the preferred embodiment of the invention and selected modifications thereof, fig. The working principle of the ballistic galvanometer is very simple. Damping of the ballistic galvanometer is made small to a get first. Classification, absolute and secondary instruments, indicating instruments. Dual signal see and hear when the wrench has reached the selected torque.
Mt torque in nmm l extrusion length in mm it torsional moment in cm4 g 26000 nmm2. The system producing the deflecting force is called deflecting system or moving system. A common steerable catheter is constructed by braiding. The wider base of the conical arm is bolted to the fin shaft see fig. The torque due to a force depends of the magnitude of the applied force, the forces point of application, and the forces direction. Deflecting torquesystem in indicating measuring instruments. Engineering fundamentals of threaded fastener design and. The coil winding are arranged such that the two torques produced, are opposite to each other and therefore pointer will take a position where the two torques are equal. When the torques are balanced the moving coil will stopped and its angular deflection represent the amount of electrical current to be measured against a fixed reference, called a scale. Dynamometer type wattmeter construction and working. Deflecting torque,controlling torque n damping torque. Controlling torque in indicating measuring instrument. Browse warren and brown deflecting beam torque wrenches in the wilmington instrument co.
The deflecting torque can be produced by utilizing any of the effects. The em torque is counterbalance by the mechanical torque of control springs attached to the movable coil also. Due to iron core, the deflecting torque increase, increasing the sensitivity of the instrument. In gravity control, a small weight is placed on an arm attached to the deflecting system. The defecting beam torque wrench is a type of torque wrench that will indicate the level or size of the tightness of the nut or bolt that is tightened from the pointer rod. Deflecting, controlling and damping torque engineering notes. A deflecting or operating torque 2 a controlling or. On the deflecting lever are a signal processing unit, a communication unit and a calibration unit. Now there are two deflecting torques one is acting on the coil 1 and another is acting on the coil 2. As it has very high traffic, therefore sometimes it may be difficult to download then you have to do this in diffrent attempts. The figure right side shows the pointer at zero position. The deflecting torque is produced by the electromagnetic action of the current. Deflecting torque article about deflecting torque by the. Under the action of deflecting torque, the pointer will continue to move indefinitely and shall be independent of the value of electrical quantity to be measured.
Email this page download pdf download pdf printable page. Uniti measuring instruments classification deflecting, control and damping torques ammeters and voltmeters pmmc, moving iron type instruments expression for the deflecting torque and control torque errors and compensations, extension of range using shunts and series resistance. Deflecting controlling damping torque your electrical guide. Moving iron instruments are generally used to measure alternating voltages and currents.
Permanent magnet moving coil mechanism pmmc mathematical. Deflecting, controlling and damping torques deflecting torque. Deflection by force f deflection by force f deflection by force f deflection under own weight deflection under own weight deflection under own weight bending stress. This results in a high power loss to the circuit to which the instrument is connected. Warren and brown deflecting beam torque wrenches on.
Click here to download the pdf of this topic moving iron instruments. The deflecting torque provides some deflection and controlling torque acts in the opposite direction to that of deflecting torque. An ammeter has a pmmc instrument with a coil resistance of r m. Application of composite deflecting model in horizontal.