"Tachometer A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes from Greek ""ταχος"" (""tachos"" ""speed"") and ""metron"" (""measure""). Essentially the words tachometer and speedometer have identical meaning: a device that measures speed. It is by arbitrary convention that in the automotive world one is used for engine and the other for vehicle speed. In formal engineering nomenclature, more precise terms"
"used to synchronize several tape machines together, but only if in addition to the tach signal, a directional signal is transmitted, to tell slave machines in which direction the master is moving. Tachometer A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes from Greek ""ταχος"" (""tachos"" ""speed"") and ""metron"" (""measure""). Essentially the words tachometer and speedometer have identical meaning: a"
"To create different pressure ranges, the spring rate can be increased or decreased. The spinning-rotor gauge works by measuring the amount a rotating ball is slowed by the viscosity of the gas being measured. The ball is made of steel and is magnetically levitated inside a steel tube closed at one end and exposed to the gas to be measured at the other. The ball is brought up to speed (about 2500 rad/s), and the speed measured after switching off the drive, by electromagnetic transducers. The range of the instrument is 10 to 10 Pa (10 Pa with less accuracy)."
"Rotameter A rotameter is a device that measures the volumetric flow rate of fluid in a closed tube. It belongs to a class of meters called variable area meters, which measure flow rate by allowing the cross-sectional area the fluid travels through to vary, causing a measurable effect. The first variable area meter with rotating float was invented by Karl Kueppers in Aachen in 1908. This is described in the German patent 215225. Felix Meyer founded the company """"Deutsche Rotawerke GmbH"""" in Aachen recognizing the fundamental importance of this invention. They improved this invention with new shapes of the float"
"Phase shift torque measurement Phase shift torque measurement is carried out by a torquemeter that uses a shaft connected between rotating machines such as a turbine and compressor or jet engine under test and a dynamometer. A gear at each end of the shaft is surrounded by a coil. The gear produces a sine wave in the coil's eddy current magnetic field. Under no load the waves are in line with each other, as a load is applied to the shaft the waves shift out of phase with each other. Using Young's modulus calculations for the stiffness of the material"
"the load or torque through the shaft can be measured highly accurately at speeds up to 150,000 rpm and torque up to 400,000 Nm. Phase shift torque measurement Phase shift torque measurement is carried out by a torquemeter that uses a shaft connected between rotating machines such as a turbine and compressor or jet engine under test and a dynamometer. A gear at each end of the shaft is surrounded by a coil. The gear produces a sine wave in the coil's eddy current magnetic field. Under no load the waves are in line with each other, as a load"
"rotating as fluid passes through them. There are various types of gear meters named mostly for the shape of the internal components Two rotating oval gears with synchronized teeth “squeeze” a finite amount of fluid through the meter for each revolution. With oval gear flow meters, two oval gears or rotors are mounted inside a cylinder. As the fluid flows through the cylinder, the pressure of the fluid causes the rotors to rotate. As flow rate increases, so does the rotational speed of the rotors. Helical gear flow meters get their name from the shape of their gears or rotors."
"Rotor current meter A rotor current meter (RCM) is a mechanical current meter, an oceanographic device deployed within an oceanographic mooring measuring the flow within the world oceans to learn more about ocean currents. Many RCMs have been replaced by instruments measuring the flow by hydroacoustics, the so-called Acoustic Doppler Current Profilers. However, for instance in Fram Strait, the Alfred Wegener Institute still uses RCMs for long-term monitoring the inflow into the Arctic Ocean. A RCM usually consists of the recording unit, a propeller to detect the water velocity and vane to determine the direction of the flow. The gimbal"
"Inertial reference unit An inertial reference unit (IRU) is a type of inertial sensor which uses gyroscopes (electromechanical, ring laser gyro or MEMS) and accelerometers (electromechanical or MEMS) to determine a moving aircraft’s or spacecraft’s change in rotational attitude (angular orientation relative to some reference frame) and translational position (typically latitude, longitude and altitude) over a period of time. Another name often used interchangeably with IRU is Inertial Measurement Unit. The two basic classes of IRUs/IMUs are ""gimballed"" and ""strapdown"". The older, larger gimballed systems have become less prevalent over the years as the performance of newer, smaller strapdown systems"
"of a rotating component not being parallel with the axis, such as a drill chuck not holding the drill exactly in line with the axis. In general, cutting tools are less tolerant of axial run-out since the tool tip tends to dig in and further increase run-out. However a shaft may be more tolerant of axial run-out since the centre of gravity is displaced less. Typically run-out is measured using a dial indicator pressed against the rotating component while it is turned. Total indicated run-out (TIR) is a technician's term for the measured run-out of any rotating system, including all"
"Tach timer The tach(ometer) timer is an instrument used in aviation to accumulate the total number of revolutions performed by the engine. The unit of measure is equivalent to the number of hours of running at a certain, specific reference speed of rotation. If the reference speed of rotation is 2400 RPM then the timer runs in real time when the engine is running at 2400 RPM, half speed while the engine is run at 1200 RPM (a fast idle for some aviation engines) or at 5/6ths real time at 2000 RPM (a slow cruise speed). The tach timer integrates"
"Rotary encoder A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to analog or digital output signals. There are two main types of rotary encoder: absolute and incremental. The output of an absolute encoder indicates the current shaft position, making it an angle transducer. The output of an incremental encoder provides information about the ""motion"" of the shaft, which typically is processed elsewhere into information such as position, speed and distance. Rotary encoders are used in a wide range of applications that require monitoring or"
"Rotating disk viscometer The Rotating disk viscometer, or ""Mooney Machine"" as it is sometimes referred to in the rubber industry, is the standard viscometer for measuring material viscosity and scorch time for rubber before vulcanization. It was developed in the 1930s by Melvin Mooney. For a specific temperature, scorch time describes how long it will take the material to vulcanize. For example, a scorch time at ambient temperature indicates the rubber will be able to remain unvulcanized at room temperature for an extended period of time. The Mooney machine itself consists of a cylindrical, serrated, metal disk designed to hold"
"These rotors resemble the shape of a helix, which is a spiral-shaped structure. As the fluid flows through the meter, it enters the compartments in the rotors, causing the rotors to rotate. Flowrate is calculated from the speed of rotation. A disk mounted on a sphere is “wobbled” about an axis by the fluid flow and each rotation represents a finite amount of fluid transferred. A nutating disc flow meter has a round disc mounted on a spindle in a cylindrical chamber. By tracking the movements of the spindle, the flow meter determines the number of times the chamber traps"
"has improved greatly via the use of solid-state sensors and advanced real-time computer algorithms. Gimballed systems are still used in some high-precision applications where strapdown performance may not be as good. Inertial reference unit An inertial reference unit (IRU) is a type of inertial sensor which uses gyroscopes (electromechanical, ring laser gyro or MEMS) and accelerometers (electromechanical or MEMS) to determine a moving aircraft’s or spacecraft’s change in rotational attitude (angular orientation relative to some reference frame) and translational position (typically latitude, longitude and altitude) over a period of time. Another name often used interchangeably with IRU is Inertial Measurement"
"the vessels holding the liquids. The nutating motion is widely employed in flowmeters and pumps. The displacement of volume for one revolution is first determined. The speed of the device in revolutions per unit time is measured. In the case of flowmeters, the product of the rotational speed and the displacement per revolution is then taken to find the flow rate. A nutating disc engine was patented in 1993 and a prototype was reported in 2006. The engine consisted of an internal disk wobbling on a Z-shaped shaft. Nutation has also been used in drive systems for gearboxes, with proposed"
"are typically stated: angular speed of servo shaft rotation and mechanical torque produced on the shaft. Speed is expressed as a time interval that a servo requires in order to rotate the shaft for 60° angle. Torque is expressed as weight that can be pulled up by the servo if it hangs from a pulley with a certain radius mounted on the shaft. For example, if a servo model is described as ""0.2 s / 2 kg"", that should be interpreted as ""This servo rotates the shaft for 60° in 0.2 seconds, and it is able to pull up 2"
"the vibrations detected, they calculate the part's unbalance. Many times these devices contain a spectrum analyzer so the part condition can be monitored without the use of a photocell and non-rotational vibration can be analyzed. Balancing machine A balancing machine is a measuring tool used for balancing rotating machine parts such as rotors for electric motors, fans, turbines, disc brakes, disc drives, propellers and pumps. The machine usually consists of two rigid pedestals, with suspension and bearings on top supporting a mounting platform. The unit under test is bolted to the platform and is rotated either with a belt-, air-,"
"meter which allows to keep the abbreviation RCM. Rotor current meter A rotor current meter (RCM) is a mechanical current meter, an oceanographic device deployed within an oceanographic mooring measuring the flow within the world oceans to learn more about ocean currents. Many RCMs have been replaced by instruments measuring the flow by hydroacoustics, the so-called Acoustic Doppler Current Profilers. However, for instance in Fram Strait, the Alfred Wegener Institute still uses RCMs for long-term monitoring the inflow into the Arctic Ocean. A RCM usually consists of the recording unit, a propeller to detect the water velocity and vane to"
"of cars. Yaw-rate sensor A yaw-rate sensor is a gyroscopic device that measures a vehicle’s angular velocity around its vertical axis. The angle between the vehicle's heading and vehicle actual movement direction is called slip angle, which is related to the yaw rate. There are basically two types of Yaw rate sensors: piezoelectric type and micromechanical type. In the piezoelectric type, the sensor is a ""tuning fork""-shaped structure with four piezo elements (two on top and two below). During straight ahead driving, the upper ones produce no voltage as no Coriolis force acts. But in cornering, the rotational movement causes"
"Yaw (rotation) A yaw rotation is a movement around the yaw axis of a rigid body that changes the direction it is pointing, to the left or right of its direction of motion. The yaw rate or yaw velocity of a car, aircraft, projectile or other rigid body is the angular velocity of this rotation, or rate of change of the heading angle when the aircraft is horizontal. It is commonly measured in degrees per second or radians per second. Another important concept is the yaw moment, or yawing moment, which is the component of a torque about the yaw"
"velocity. The corresponding basic SI derived unit is s or Hz. When measuring angular speed, the unit radians per second is used. Formally, hertz (Hz) and radian per second (rad/s) are two different names for the same SI unit, s. However, they are used for two different but proportional ISQ quantities: frequency and angular frequency (angular speed, magnitude of angular velocity). The conversion between a frequency (measured in hertz) and an angular velocity (measured in radians per second) are: Thus a disc rotating at 60 rpm is said to be rotating at either 2 rad/s or 1 Hz, where the"
"former measures the angular velocity and the latter reflects the number of revolutions per second. If the non-SI unit rpm is considered a unit of frequency, then . If it instead is considered a unit of angular velocity and the word ""revolution"" is considered to mean 2 radians, then . Revolutions per minute Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min) is the number of turns in one minute. It is a unit of rotational speed or the frequency of rotation around a fixed axis. According to the International System of Units (SI), rpm is"
"their cycle. A type of pneumatic motor, known as a rotary vane motor, uses air to produce rotational motion to a shaft. The rotating element is a slotted rotor which is mounted on a drive shaft. Each slot of the rotor is fitted with a freely sliding rectangular vane. The vanes are extended to the housing walls using springs, cam action, or air pressure, depending on the motor design. Air is pumped through the motor input which pushes on the vanes creating the rotational motion of the central shaft. Rotation speeds can vary between 100 and 25,000 rpm depending on"
"Governor (device) A governor, or speed limiter or controller, is a device used to measure and regulate the speed of a machine, such as an engine. A classic example is the centrifugal governor, also known as the Watt or fly-ball governor on a reciprocating steam engine, which uses the effect of centrifugal force on rotating weights driven by the machine output shaft to regulate its speed by altering the input flow of steam. Centrifugal governors were used to regulate the distance and pressure between millstones in windmills since the 17th century. Early steam engines employed a purely reciprocating motion, and"
"Current meter A current meter is oceanographic device for flow measurement by mechanical (rotor current meter), tilt (Tilt Current Meter), acoustical (ADCP) or electrical means. In physics, one distinguishes different reference frames depending on where the observer is located, this is the basics for the Lagrangian and Eulerian specification of the flow field in fluid dynamics: The observer can be either in the Moving frame (as for a Lagrangian drifter) or in a resting frame. Mechanical current meters are mostly based on counting the rotations of a propeller and are thus rotor current meters. A mid-20th-century realization is the Ekman"
"working on further improvements of these sophisticated state-of-art technologies. Safran and Northrop Grumman are the major manufacturers of HRG. A wheel is driven to rotate a fraction of a full turn about its axis. The tilt of the wheel is measured to produce a signal related to the rate of rotation. Inexpensive vibrating structure microelectromechanical systems (MEMS) gyroscopes have become widely available. These are packaged similarly to other integrated circuits and may provide either analog or digital outputs. In many cases, a single part includes gyroscopic sensors for multiple axes. Some parts incorporate multiple gyroscopes and accelerometers (or multiple-axis gyroscopes"
"Direct observation of the vibratory motion of a machine's shaft is desirable because most often, the shaft is the source of vibration in the machine. Previous to the introduction of the so-called ""Bently probe,"" this shaft motion had to be indirectly inferred by measuring the vibration of the machine's casing. While machinery casing measurements can be valuable under certain conditions, machines that employ fluid bearings generally have damping and stiffness characteristics that do not adequately transmit shaft vibration to the machine's casing. Consequently, direct observation of the machine's shaft (rotor) was recognized as a more accurate method of assessing condition"
"Cobra probe A Cobra probe is a device to measure the pressure and velocity components of a moving fluid. It is a multi-holed pressure probe with rotational axis of the probe shaft coplanar with the measurement plane of the instrument. Because of this geometry, when the instrument is rotated around the shaft's axis, the measurement elements of the probe remain in the same location. The name cobra probe comes from the shape of the probe head which gives it this property. Cobra probes come in three-, four-, and five-hole configurations, the former used for two-dimensional flow measurement, the latter two"
"Spinner's weasel Spinner's weasel or clock reel is a mechanical yarn-measuring device consisting of a spoked wheel with gears attached to a pointer on a marked face (which looks like a clock) and an internal mechanism which makes a ""pop"" sound after the desired length of yarn is measured (usually a skein). The pointer allows the spinner to see how close she/he is to reaching a skein. The weasel's gear ratio is usually 40 to 1, and the circumference of the reel is usually two yards, thus producing an 80-yard skein when the weasel pops (after 40 revolutions). Some reels"
"and the averages are stored. The rotation of the propeller sensors is detected by the magnetodiodes. As a result of the asymmetry in placement of the magnetodiodes, a staggered pair of pulses is produced each quarter revolution; the phase relationship indicates the sense of direction of rotation and the pulse rate indicates the rate of rotation. In order to calculate and record the velocity components, the vector averaging circuitry is turned on by a rotor count, which is signaled by a proper sequence of changes in the levels of the magnetodiodes. The instrument heading (formula_1) is determined and stored in"
"Yaw-rate sensor A yaw-rate sensor is a gyroscopic device that measures a vehicle’s angular velocity around its vertical axis. The angle between the vehicle's heading and vehicle actual movement direction is called slip angle, which is related to the yaw rate. There are basically two types of Yaw rate sensors: piezoelectric type and micromechanical type. In the piezoelectric type, the sensor is a ""tuning fork""-shaped structure with four piezo elements (two on top and two below). During straight ahead driving, the upper ones produce no voltage as no Coriolis force acts. But in cornering, the rotational movement causes the upper"
"other cylinder round, and the force it exerts on that cylinders (torque) is measured, which can be converted to a shear stress. One version of this is the Fann V-G Viscometer, which runs at two speeds, (300 and 600 rpm) and therefore only gives two points on the flow curve. This is sufficient to define a Bingham plastic model which used to be widely used in the oil industry for determining the flow character of drilling fluids. In recent years rheometers that spin at 600, 300, 200, 100, 6 & 3 RPM have been used. This allows for more complex"