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 fall into five categories, conductivity sensors, piezoelectric sensors, Metal Oxide Field Effect Transistors (MOSFETs), optical sensors, and these employing spectrometry-based sensing methods.
Conductivity sensors could be made from metal oxide and polymer elements, both of which exhibit a modification of resistance when exposed to Volatile Organic Compounds (VOCs). In this report only Metal Oxide Semi-conductor (MOS), Weight Sensor and Quartz Crystal Microbalance (QCM) will be examined, as they are well researched, documented and established as vital element for various types of machine olfaction devices. The application form, where proposed device is going to be trained to analyse, will greatly influence the choice of sensor.
A torque sensor, torque transducer or torque meter is actually a device for measuring and recording the torque on a rotating system, such as an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or cap torque tester. Static torque is comparatively easy to measure. Dynamic torque, on the contrary, is difficult to measure, because it generally requires transfer of some effect (electric, hydraulic or magnetic) from the shaft being measured to your static system.
One method to achieve this would be to condition the shaft or perhaps a member connected to the shaft with several permanent magnetic domains. The magnetic characteristics of those domains will vary in accordance with the applied torque, and therefore could be measured using non-contact sensors. Such magnetoelastic torque sensors are generally employed for in-vehicle applications on racecars, automobiles, aircraft, and hovercraft.
Commonly, torque sensors or torque transducers use strain gauges placed on a rotating shaft or axle. With this particular method, a means to power the strain gauge bridge is essential, in addition to a methods to get the signal through the rotating shaft. This could be accomplished using slip rings, wireless telemetry, or rotary transformers. Newer varieties of torque transducers add conditioning electronics plus an A/D converter to the rotating shaft. Stator electronics then browse the digital signals and convert those signals to Compression Load Cell, like /-10VDC.
A much 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 may be read remotely and output without the need for attached electronics on the shaft. The probable first use within volume will be in the automotive field as, of May 2009, Schott announced it has a SAW sensor package viable for in vehicle uses.
Another way to measure torque is by way of twist angle measurement or phase shift measurement, whereby the angle of twist resulting from applied torque is measured by making use of two angular position sensors and measuring the phase angle between the two. This technique is utilized in the Allison T56 turboprop engine.
Finally, (as described within the abstract for people Patent 5257535), in the event the mechanical system involves the right angle gearbox, then the axial reaction force experienced by the inputting shaft/pinion could be linked to the torque gone through by the output shaft(s). The axial input stress must first be calibrated up against the output torque. The input stress can be simply measured via strain gauge measurement in the input pinion bearing housing. The output torque is readily measured utilizing a static torque meter.
The torque sensor can function like a mechanical fuse and it is a key component to get accurate measurements. However, improper installing of the torque sensor can damage 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 of the torque sensor as well as its reading accuracy is going to be afflicted with the style of the Tension Compression Load Cell. The shaft becomes unstable on the critical speed from the driveline to result in torsional vibration, which can harm the torque sensor. It is required to direct the strain for an exact point for accurate torque measurement. This time is normally the weakest point of the sensor structure. Hence, the torque sensor is purposely designed to be one of many weaker elements of the driveline.