There are a number of different types of sensors which can be used as essential components in various 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 composed of metal oxide and polymer elements, each of which exhibit a modification of resistance when subjected to Volatile Organic Compounds (VOCs). Within this report only Metal Oxide Semi-conductor (MOS), Load Cell and Quartz Crystal Microbalance (QCM) is going to be examined, since they are well researched, documented and established as essential element for various types of machine olfaction devices. The application form, where the proposed device is going to be trained onto analyse, will greatly influence the choice of sensor.
A torque sensor, torque transducer or torque meter is really a device for measuring and recording the torque on a rotating system, like an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or cap torque tester. Static torque is fairly easy to measure. Dynamic torque, on the contrary, can be difficult to measure, since it generally requires transfer of some effect (electric, hydraulic or magnetic) from your shaft being measured to a static system.
One method to achieve this would be to condition the shaft or perhaps a member linked to the shaft with a series of permanent magnetic domains. The magnetic characteristics of such domains will be different according to the applied torque, and thus could be measured using non-contact sensors. Such magnetoelastic torque sensors are usually utilized 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. Using this method, a method to power the strain gauge bridge is necessary, in addition to a means to have the signal through the rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer types of torque transducers add conditioning electronics as well as an A/D converter towards the rotating shaft. Stator electronics then read the digital signals and convert those signals to Compression Load Cell, like /-10VDC.
A much more recent development is the usage of SAW devices linked to the shaft and remotely interrogated. The strain on these tiny devices as the shaft flexes may 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.
An additional way to measure torque is by means of twist angle measurement or phase shift measurement, whereby the angle of twist caused by applied torque is measured by making use of two angular position sensors and measuring the phase angle between the two. This method is utilized in the Allison T56 turboprop engine.
Finally, (as described in the abstract for US Patent 5257535), when the mechanical system involves the right angle gearbox, then the axial reaction force experienced by the inputting shaft/pinion could be related to the torque experienced by the output shaft(s). The axial input stress must first be calibrated from the output torque. The input stress can easily be measured via strain gauge measurement from the input pinion bearing housing. The output torque is easily measured utilizing a static torque meter.
The torque sensor can function like a mechanical fuse and it is a vital component to obtain accurate measurements. However, improper installing of the torque sensor can damage the device permanently, costing money and time. Hence, cdtgnt torque sensor has to be properly installed to ensure better performance and longevity.
The performance and longevity in the torque sensor along with its reading accuracy will likely 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 damage the torque sensor. It is necessary to direct the strain with an exact point for accurate torque measurement. This time is usually the weakest point of the sensor structure. Hence, the torque sensor is purposely made to be one of many weaker components of the driveline.