Torque meter

Power. There are two main ways to measure the power deUvered by the driver to the pump. The first method is to install a torque meter between the pump and the driver. A torque meter is a rotating bat having a strain gauge to measure shear deformation of a torqued shaft. Discussion of the principle of torque meter operation is available (16). The benefit of this method is direct and accurate measurements. The power deUveted to the pump from the driver is calculated from torque, T, and speed (tpm) in units of brake horsepower, ie, BHP (eq. 4a) when Tis in lbs-ft, and kW (eq. 4b) when T is N-m. 

The disadvantages of this method ate the need for a torque meter, longer total length of the pumping unit, and greater susceptibiUty to misalignment and vibrations. This method is used only at a manufacturer s test faciUties or research laboratories. It is not used in the field. 

If the pump manufacturer uses motors for pump power measurement, these motors ate caUbrated to determine the horsepower from the electric power reading and caUbration curves. Such test motors ate recaUbrated periodically, ensuring the same degree of accuracy as shown by the torque meters. 

Where a torque meter is available to monitor expander shaft horsepower, this option is preferred over the addition of items 1, 2, and 3. 

Rgure 8-31. Multiple diaphragm flexible element coupling with a strain gauge type torque meter. Courted ofZum Industrie Inc., Mechanical Drives DMsforii... 

One of the critical measurements is torque or shaft power. A variety of methods is recognized direct methods such as torque meters or reaction mounted drivers (dynamometers) and indirect methods such as electrical power input to drive motors, heat balance, or heat input to a loop cooler. See Part 7, Measurement of Shaft Power, PTC 19.7 1961 [3] for additional information. 

Torque-actuated valves for lab-on-a-chip, 26 975 Torque meter, 21 58 Torque motor, enhanced, 23 870 Torsemide, 5 169... 

Fig. 2. Schematic diagram of the equipment for granulation tests (1) granulator drum, (2) pneumatic nozzles, (3) engine, (4) inverter, (5) tripod, (6) rotameters, (7) water tank, (8) compressor, (9) tachometer, (10) torque meter, (11) reader, and (12) computer.

Murray, B.C. and Wickett, R.R. Correlation between Dermal Torque Meter, Cutometer, and Dermal Phase Meter measurements of human skin. Skin Res. Technol. 1997, 3 101-6. 

FIGURE 31.16 Effect of emollient BW on elastic properties of skin, as measured using Dermal Torque Meter, over a 6-h period following a single wash event. Ue and Ur refer to the immediate elastic extension and recovery, respectively. 

Boyce, S.T., Supp, A.P., Wickett, R.R., Hoath, S.B., and Warden, G.D. Assessment with the dermal torque meter of skin pliability after treatment of burns with cultured skin substitutes. J. Bum. Care Rehab ll. 2000 21 55-58. 

The problem of copolymer characterization becomes more acute when on-line process measurements are required. Most of the process instrumentation available yields measurements which are functions of the molecular weight, copolymer composition and, in some cases, of the microstructure of the polymer molecules. Such is the case for on-line viscosimeters, densitometers, torque meters etc. Clearly, the development of copolymer characterization techniques in general and on-line instrumentation in particular requires extensive development. 

Fig.l Schematic diagram of experimental apparatus. (1) Two-dimensional internal mixer (2) variable-speed mixer (3) torque meter (4) recorder (5) video camera (6) light source (7) pressure transducer (8) strain amplifier (9) photo recorder (10) thermocouple (11) cold junction (12) bridge conditioner. 

The mentioned back-to-back test bed is shown in Pig. P-46. It consists of two identical gearboxes that are mechanically coupled with a torque meter device on the low-speed shafts and with a special highest speed toothed coupling on the highspeed shafts. 

All shafts equipped with instruments are hoUow to take all the cables which are connected via special high-speed slip rings to the static analysis instruments. Rotor vibrations are to be surveyed by pic-up s all other instruments and sensors are as for a common industrial platform gear. The wheel of the slave gear is not equipped with sensors, but the hydraulic axial force device and the input motor drive are connected to it. At the input shaft, the total losses of both gears can be measimed by means of a torque meter coupling. 

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