Data Acquisition Systems For Flatness.

EVE is a stand alone measurement solution and data acquisition system combining incredible power, amazing simplicity and unlimited versatility. Eve is compatible with virtually any sensor along with the entire line of MTII?s non-contact displacement sensors, allowing correlation of displacement, temperature, pressure and other physical parameters for your test, research or process monitoring application.

Flatness can also be analyzed with the minimum zone calculation method. The surface data to be analyzed is enclosed by two parallel planes with only minimal separation. The level of flatness or flatness error is then indicated by the amount of separation between the two planes.

Surface flatness is a common measurement specification over a wide range of manufacturing industries. Flatness critically affects, for example, the reliability and assembly yield of electronic products, the cosmetic appearance and handling characteristics of paper products, and the mechanical fit and functionality of fabricated metal components. Non-flatness, or warpage, is a frequent problem in manufacturing, due to inadequacies in design, materials, and/or processing of components. The ability to distinguish and reject components whose non-flatness exceeds user specifications is valuable on the production line because it allows the manufacturer or user to avoid problems in later manufacturing steps, maintain product quality, and recognize processing problems early.

National Semiconductor introduces three new energy-efficient, high-speed differential amplifiers that are well-suited for a wide variety of communications, test, instrumentation, defence and space applications. These amplifiers are part of National's PowerWise line of energy-efficient analogue integrated circuits that deliver outstanding performance-to-power ratios. The LMH6552 is a high-bandwidth, current feedback differential amplifier at 1.5 GHz, with low power consumption at 112 mW. The LMH6515 digital-controlled variable gain amplifier offers 8 dB noise figure and a 40 dBm output intercept point (OIP3) at 70 MHz for WCDMA, GSM and WiMAX receiver signal paths. The LMH6555 enables an 8-bit, 3 Giga-sample data acquisition system with less than half the power consumption of competitive solutions.

Other measurement tools, such as profilemeters provide 2-D data by dragging a stylus across the part surface. This limits the amount of data per unit time, Three-dimensional measurement delivers greater process knowledge. The Simetra scans through both sides of the entire part concurrently and can display up to 8,000 data points per side in about 10 seconds. You can see the 3-D flatness of both sides of a part, not just 2-D profile lines.

As shown in Fig. there is a reflection mirror inside the system, which is controlled by a motor. This mechanism allows changing the oblique angle to alter the measurement sensitivity. Therefore, the system can handle various surface conditions, such as different measurement accuracy and flatness. Based on OPTON's unique image processing software, approximately 300,000 points can be measured in 10 seconds from one image. In addition, a standard target is used to adjust the tilting of the optical parts to ensure the total measurement accuracy.

Akrometrix' LineMoir product line enables manufacturers to cost effectively measure, analyze and react to board-to-board and lot-to-lot variations in substrate flatness. Whether in a stand-alone or in a high volume application, manufacturers receive real-time data to make substrate specific decisions (pass/fail), monitor trending (SPC), identify key correlations between flatness and assembly defects and enable traceability. All of these capabilities empower engineers and managers to better understand processes and materials, improve first pass yields and provide a definitive competitive advantage in the marketplace.

One problem discovered was tilted parts, which resulted in uneven disc wear that left two thin-to-high spots. These anomalies produce audible oscillations plus multiple harmonics, which are annoying and indicate the malfunction. Another problem came from unbalanced rotors that had to be replaced. Before the IOtech system was used, the brakes were removed from a vehicle, sent to a lab for tests, and the data recorded and analyzed. The process took about a week. With the new system in the field, a vehicle is put on a hoist, the wheel is spun, and the data is recorded and analyzed within about 5 minutes, a remarkable reduction in time, labor, and ultimate cost.

With the LAZER GRAZER, matte, semi-matte, or polished surfaces can be checked for flatness of virtually any material. Very difficult substrates such as ceramics, graphite, tungsten carbide and silicon carbide can be evaluated with ease. Even machined metal surfaces can be tested. The high contrast fringes produced by Lazer GRAZER will assist in fine-tuning the production process and increasing both quality and through-put.

Currently, many brake rotors are inspected on the vehicle with a dial indicator magnetically fastened to a suspension component. The dial indicator reading is recorded while rotating the wheel, but the method provides only runout data for one brake plate. When further investigation is needed, the rotor is removed from the vehicle and sent to the OEM or supplier's warranty center where a precision spindle and a controller are used to rotate the rotor at a constant speed. The typical measurement process involves off-the-shelf roundness instruments with linear variable differential transformers, signal conditioners, and a read-out device that allows technicians to manually measure and record the roundness, flatness, and thickness of brake discs.

When used with Lapmaster Optical Flats, contrasting light and dark bands are readily observed on most reflective or semi-reflective surfaces. Surface flatness to within .000001" is quickly and easily measured on parts ranging in size up to 10[.]5" in diameter.

In addition, some samples cannot readily be stopped and started because of sample characteristics, such as high weight, and/or the requirements of the remainder of the production line. Because the above-described techniques require a stationary support structure to hold the sample in place during data acquisition and/or grating / sample translation, they cannot readily be applied to measure surface flatness of continuously moving samples.

In view of the foregoing, a need exists in the art for a system and method for measuring surface flatness of continuously moving samples. In addition, a need exists for such a system and method to be efficient and cost-effective.

Lapmaster International's SPI Interferometers with grazing incidence are a inexpensive, fast and accurate means for flatness inspection of ground, fine-ground, lapped or polished parts. The flatness reading of a non-reflective ground surfaces (most materials) are clearly displayed as fringe-pattern topography on an accompanying monitor. Eliminate the need for secondary polishing operations when the only purpose is to generate a reflective finish for optical flatness measurement. Whether used directly next to the lapping, fine-grinding, grinding machine or inspection lab, the Lapmaster SPI interferometer is a cost-effective solution for simple flatness qualification requirements. An optional printer provides documentation of the flatness readings. This instrument is an excellent platform for both qualitative (go/no-go) as well as quantitative flatness measurements.

Getting data involves handling/presentation of the sample to the measurement head. A phase-stepping process that involves multiple image collection (approximately 3), and algorithmic processing of the images collected to create an out-of-plane displacement matrix for the surface under investigation. Speed (1 second data acquisition regardless of area), resolution (2.5 microns or better) and cost are core advantages to the technique.

Bosch Braking Systems in cooperation with Digital Metrology Solutions, designed a measurement system for evaluating brake components returned under warranty. The new system using an IOtech WaveBook and capacitive or LVDT displacement sensors moved the static test from the lab bench to a garage hoist or the highway where dynamic tests can be run on actual vehicles. This reduces the test time from weeks to minutes: It eliminates the time and huge expense needed to remove the components from the vehicle, run the bench test, and return the parts to the point of origin. The new test system produces more in-depth data in a uniform format, and is remarkably faster and much more accurate.

A newer and more complex arrangement eliminates the slip rings by embedding sophisticated signal-conditioning circuits within the measurement roller. These circuits digitize the measured quantities and transmit the data via optical couplers to additional stationary electronics nearby. To completely eliminate slip rings, the power for the embedded sensors and signal-conditioning circuits can be magnetically coupled into the roller.

Applications particularly suited for neural networks are those in which mathematical formulation is very hard or impossible. Some examples are signal analysis and processing, process control, robotics, data classification, data smoothing, pattern recognition, image analysis, speech analysis, medical diagnostics, stock market forecasting, analysis for loan or credit solicitations, and oriented marketing.

In contrast, the measurement roller used by UEI and Sendzimir contains no sensors or electronics and is supported along its length, typically at intervals of 2 in. or less, by assemblies that resemble old-fashioned upside-down roller skates?the kind with a wheel at each of the four corners. Except for a minuscule amount of up-and-down travel, these assemblies remain stationary; each one sits atop a load cell that measures the force exerted by the skate it supports.

Various systems have been developed for measuring the surface flatness of a work piece. Applications for such systems cover a wide range of products on which a flat surface is desired. One system which is employed in the steel sheet industry uses mechanical scanning. In this system a single transducer or a small number of transducers, such as a laser distance sensor or a capacitance sensor is moved over the sheet surface to provide an output indicative of variations in the flatness of the sheet. Systems of this type require considerable skill to operate in order to meet the necessary standards of accuracy required.