There are a number of different types of sensors which can be used as essential components in different designs for machine olfaction systems. Electronic Nose (or eNose) sensors belong to five categories, conductivity sensors, piezoelectric sensors, Metal Oxide Field Effect Transistors (MOSFETs), optical sensors, and these employing spectrometry-based sensing methods.
Conductivity sensors may be made from metal oxide and polymer elements, both of which exhibit a modification of resistance when subjected to Volatile Organic Compounds (VOCs). In this particular report only Metal Oxide Semi-conductor (MOS), Load Cell and Quartz Crystal Microbalance (QCM) is going to be examined, because they are well researched, documented and established as important element for various machine olfaction devices. The application form, where the proposed device will likely be trained onto analyse, will greatly influence deciding on a sensor.
A torque sensor, torque transducer or torque meter is really a device for measuring and recording the torque over a rotating system, like an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or cap torque tester. Static torque is relatively very easy to measure. Dynamic torque, on the other hand, can be difficult to measure, as it generally requires transfer of some effect (electric, hydraulic or magnetic) through the shaft being measured to some static system.
One method to accomplish this would be to condition the shaft or even a member connected to the shaft with a number of permanent magnetic domains. The magnetic characteristics of such domains can vary in accordance with the applied torque, and therefore may be measured using non-contact sensors. Such magnetoelastic torque sensors are typically employed for in-vehicle applications on racecars, automobiles, aircraft, and hovercraft.
Commonly, torque sensors or torque transducers use strain gauges applied to a rotating shaft or axle. With this method, a method to power the strain gauge bridge is necessary, as well as a methods to get the signal from the rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer types of torque transducers add conditioning electronics plus an A/D converter for the rotating shaft. Stator electronics then read the digital signals and convert those signals to Compression Load Cell, such as /-10VDC.
A far more recent development is the use of SAW devices linked to the shaft and remotely interrogated. The force on these tiny devices as the shaft flexes can be read remotely and output without resorting to attached electronics on the shaft. The probable first utilization in volume are usually in the automotive field as, of May 2009, Schott announced it possesses a SAW sensor package viable for in vehicle uses.
A different way to measure torque is by means of twist angle measurement or phase shift measurement, whereby the angle of twist as a result of applied torque is measured by utilizing two angular position sensors and measuring the phase angle between them. This method is used within the Allison T56 turboprop engine.
Finally, (as described inside the abstract for people Patent 5257535), when the mechanical system involves the right angle gearbox, then the axial reaction force experienced by the inputting shaft/pinion may be related to the torque felt by the output shaft(s). The axial input stress must first be calibrated from the output torque. The input stress can be easily measured via strain gauge measurement from the input pinion bearing housing. The output torque is readily measured utilizing a static torque meter.
The torque sensor can function such as a mechanical fuse and it is a key component to have accurate measurements. However, improper setting up the torque sensor can harm the device permanently, costing time and money. Hence, cdtgnt torque sensor must be properly installed to make sure better performance and longevity.
The performance and longevity from the torque sensor and its reading accuracy will be afflicted with the style of the Force Sensor. The shaft becomes unstable in the critical speed of the driveline to result in torsional vibration, which can harm the torque sensor. It is essential to direct the strain with an exact point for accurate torque measurement. This time is usually the weakest reason for the sensor structure. Hence, the torque sensor is purposely made to be one of the weaker elements of the driveline.