Distance sensors

Laser detector Digital audio disks, video disks, laser-beam position sensors, distance sensors... 

The easiest way of measuring movement of the suds container is with distance sensors. Chapter 5.5 describes some typical examples. The advantage of these sensors is that they are also used to monitor the washing load. Their drawback is the high price. 

As a result of sensor development in the automotive industry, low-priced acceleration sensors are now available. Acceleration sensors are fundamentally also suited to observing excursion (Fig. 5.57) of the suds container caused by imbalance. However, static measurement of the weight of the washing, as achieved with a distance sensor, is not possible with acceleration sensors. 

A Rodenstock RM600 has been used to follow the shape change of chocolate and obtain an understanding of the nature of the kinetics of crystallisation of chocolates of different temper (Fryer and Pinschower 2000). The equipment consists of an optical distance sensor, with sub-micron vertical resolution, together with a traverse table which holds the sample and allows the sensor to be tracked across it. 

Fig. 14.31 16 normalized SECM approach curves recorded at -600 mV vs. Ag/AgCl with the distance sensor (d = 25 pm) of a dual microelectrode within the wells of a 96-well microtiter plate filled with phosphate-buffered saline (PBS 100pi). The normalized distance, L, is expressed as the tip-to-sample distance divided by the electrode s radius.69 Reproduced by permission of Wiley-VCH Verlag GmbH Co KGaA)... 

Initially the objective was simply to control the closing of the press to the point where the desired panel thickness was achieved. The next objective was to reduce the elosing time to maximize the press capacity. This required a more sophisticated approach to control of the press hydraulics. Distance sensors to measure the platen distance provided new opportunities for improved control. For a single opening press, position sensors allowed control of panel thickness at each sensor. 

In contrast to STM. in AFM, forces exerted by the sample on the tip (or vice versa) are recorded, and several detection schemes are possible. The AFM scans a sample with a sharp tip, which is mounted on a cantilever spring (Fig. 3). The cantilever senses the interaction forces between tip and sample. A distance sensor monitors the reflection ofthe cantilever. Nowadays, beam deflection is nearly the only used detection scheme. The laser beam is reflected onto a segmented photodiode. As the deflection ofthe cantilever changes, the laser spot on the photodiode will shift accordingly. The detected deflection is then converted into an AFM image. Due to the flexibility of AFM with respect to the nature ofthe samples that can be studied and the measuring conditions (ambient conditions, liquids, etc.), AFM is intensively used. In most... 

Equation 6 was used to calculate the sensitivity of a coil with the diameter of 11 mm and an wire diameter of 0.1 mm. The 10 turns were arranged a 2 x 5 wiring scheme in figure 1. The coil diameter is a medium diameter for eddy current distance sensors. The number of turns is chosen to provide a high inductance and resonance frequency above 10 MHz, similar to other eddy current probe experiments [7]. The wire diameter and the wiring scheme provide an compact coil, which can be manufactured using self bonding wire. 

Experiments were conducted to calibrate the PVDF sensor. To avoid the influence from the actuation voltage, we simply tapped the composite beam tip and measured simultaneously the charge amplifier output and the tip displacement. The displacement was measured with a laser distance sensor (OADM 20I6441/S14F, Baumer Electric, Southington, CT). Fig. 8.3(a) shows the measured charge response under the damped beam oscillation at 42 Hz, while Fig. 8.3(b) depicts the measured charge vs. the actual displacement, from which we can conclude that the beam tip displacement can be well captured by the PVDF sensor. 

Experiments were conducted to measure the stiffness of an IPMC beam and two IPMC-PVDF composite beams with different insulating layer thickness (30 pm vs. 100 pm). The two composite beams were named IPMC/PVDFl and IPMC/PVDF2, respectively. As illustrated in Fig. 8.5(a), the cantilevered beam under measurement was pushed quasi-statically at the tip by a linear actuator. Between the linear actuator and the tip was a PVDF-based micro force sensor measuring the interaction force. The tip displacement was measured with a laser distance sensor. Fig. 8.5(b) shows the measured tip displacement together with the corresponding force for each beam, with the spring constants determined to... 

The influence of laser-to-sample distance, sample humidity and matrix changes on the lines relative intensities are also studied. In order to compensate, at least partially, for these parameters influence, the laser-to-sample distance is controlled by an distance sensor, and a corresponding adjustment in optics height is made. The moisture content is controlled by LIBS data using H I emission line and an additional device traditionally used for online humidity control. The specific mineral matrix also affects the analytical line intensity, and usually several different minerals are present on the conveyer. Matrix changes may in certain cases be compensated by adjustments in LIBS analysis that is dependent on mineral type. Thus each mineral present in the specific rock is studied separately in order to find its individual breakdown spectrum for the sake of identification. 

On-board Local Dynamic Map. The on-board part uses merely on-board sensors that can be implemented in a real-time manner. On-board maps, for instance, are built and updated while the vehicle is driving through an unknown or previously mapped environment to realize a self-localization and mapping algorithm. Sensors that can be used for this purpose include rotary encoders like wheel encoders, incremental encoders, haU-effect sensors, mice-based odometers distance sensors like ultra-sonic sensors, infrared sensors, or depth sensors like laser or radar sensors even vision sensors can be used to analyze the optical flow for instance. In combination with an IMU device, the input data from such sensors is fused and integrated over time to create and update local onboard maps. However, without regular updates from an external reference system, such onboard-only systems are affected by increasing data error because the used models, for such onboard maps, drift over time as inaccuracies in the measured data can occur for instance. 

Collision avoidance of the base trajectory relies only on base-to-obstacle distance sensor. Consequently, if the arm is unfolded and extends beyond the base during base motion, a collision between the arm and a human is possible. A very slow base movement is tolerated. This case is the same as the example of Section 2.2. The safety invariant is The arm must not be extended beyond the base when the base is moving (with speed higher than Vq). 

Figure 21 Diboronic acid-based fluorescent PET sensors with varied interboronic acid distance. Sensor 87 demonstrated enhanced selectivity for D-sorbitol, while sensor 88 displayed neither selectivity nor sensitivity towards monosaccharides.

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