3-point Method Research Articles

3点法による寸法・形状測定に関する研究(第1報)

3点法による寸法・形状測定に関する研究(第1報)

Roundness Measurement by the Orthogonal Mixed Method. Proposal of the Orthogonal Mixed Method and Design of the Measurement System.

This paper presents a new method for roundness measurement, which is named the orthogonal mixed method. This method was developed from the mixed method that uses two displacement probes and one angle probe for measurements. The mixed method can not only separate the profile from rotational errors completely but also can detect high-frequency components having wave-lengths shorter than its probe distance. In this paper, it is verified that the best characteristics of the mixed method can be obtained in the entire frequency range if the angular distance between the displacement probe and the angle probe is set to be 90o. This orthogonal mixed method has also the simplest probe setup because it needs only one displacement probe and one angle probe to separate the profile from the rotational error. The effectiveness of the orthogonal mixed method is confirmed by comparing it with the general mixed method and the 3-point method. This paper also presents a fundamental design guide to realize the orthogonal mixed method of nanometer accuracy.

ソフトウェアデータムによる真円度測定に関する研究 混合法と３点法のシミュレーションによる比較

This paper presents a new software datum method for roundness measurement, which is called the mixed method. In this method, 2-point displacement and a tangent angle of either point are simultaneously measured using 2 probes. A differential operation of them cancels the vibrational eccentric motions due to the rotational error and a deconvoluting operation of the differential data gives the correct roundness. In this paper, the mixed method is compared with the 3-point method, the traditional method of roundness measurement, by analyzing their transfer functions, resolutions and sensitivities to some factors of errors, such as the drift, positioning error, etc. Differing from the 3-point method, the mixed method can measure high frequency components regardless of the probe distance. The mixed method can also improve its resolution in the whole frequency domain by widening the probe distance. The effectiveness and limitations of the mixed method for roundness measurement have been verified by simulations and some important information for the sensor-design of roundness measurement have been gotten by theoretical analyses.

Effects of Difference in Spatial Frequency Response of Sensors When Measuring Straightness Using Multiple Sensors.

This paper presents transfer functions that include the characteristics of sensors, in the case of measurig straightness using sensors, e.g., 2-point method. When sensors exhibit symmetrical spatial frequency response regarding the center of their aperture, difference in their spatial frequency response causes phase shift in the results of measurement. When sensors show asymmetrical response with respect to the aperture, to avoid deviation of gain in the low-frequency domain, it is important to grasp the center of gravity of sensor's intensity in the spatial domain. In the case of the 3-point method, difference in the sensors causes deviation of the transfer function of the system. However, in the case of differential laser autocollimation, the transfer function is stable.

EFFECT OF PHARMACOKINETIC SAMPLING METHODS ON AMINOGLYCOSIDE DOSING IN CRITICALLY ILL SURGERY PATIENTS

We compared pharmacokinetic parameters derived from three aminoglycoside serum concentration sampling methods and evaluated their effects on recommended aminoglycoside dosing regimens in 60 critically ill surgery patients. Patients had presumed or documented gram-negative sepsis, and had at least 4 aminoglycoside serum concentrations measured. We used a one-compartment model for peak and trough, 3-point series, and 4-point series sampling methods. Dosing regimens were calculated for each patient based on values derived from each method. We found differences in regimens for nearly 50% of patients if either 4- or 3-point series sampling was used to calculate the recommended dosage rather than peak and trough sampling. However, the 3-point method required a clinically significant change in regimen in only 12% of patients compared with 4-point sampling. The variability of all values derived from 3-point sampling were well accounted for by the 4-point method (r2 > 0.80). In addition, we noted significantly greater relative precision for 3-point sampling than peak and trough sampling for estimates of clearance, elimination rate, recommended daily dosage, and recommended dosing frequency. We recommend three optimally timed samples be drawn instead of peak and trough levels in dosing aminoglycosides in critically ill surgery patients.

Effects of Difference of Gain between Sensors when Measuring Straightness Using Multiple Sensors.

This paper presents measurement errors that are caused by difference of gain between sensors in the case of measuring straightness using multipe sensors, e. g., the 2-point method. In the case of the 2-point method and differential laser autocollimation, if there is a difference of gain between sensors, inclination of a measured surface causes quadratic error in the measurement results. And in the case of the 3-point method, it causes cubic error. This indicates means that accuracy of measurement depends on deviation from parallelism between the measured surface and the guide of sensors. Assuming that the spatial period of the measured surface is 30 or 50 times as long as the sampling interval, the difference of gain between sensors of the 2-point method or differential laser autocollimation must be within 1 or 2% to yield a gain error of measurement results within l0%. On the other hand, the difference between sensors of the 3-point method must be within 0.1 or 0.2%.

Development of posture measuring apparatus using goniometer and inclinometer. 2. Fixation, precision and calibration of goniometer

A new posture measuring apparatus was developed for time and motion study in the field of industrial health. This apparatus records working postures by measuring angles of joints and trunk inclination. The angles of joints were measured by the newly developed goniometers which use the bending loss of rubber optical fibers. This paper presents results of studies made on the fixation, precision and calibration of goniometers which are important in the actual application of this apparatus. Six freedoms of five joints were examined, i.e. elbow (flexion/extension), shoulder (abduction/adduction and horizontal adduction/abduction), hip (flexion/extension), knee (flexion/extension), ankle (dorsi-flexion/plantar-flexion). The results obtained were as follows; 1) Goniometers should be fixed according to the characteristics of each joint. 2) The output errors were calculated from the measured data, excluding the effects of flexed angles, subjects and fixations. The mean output error of all joints was 0.189 V (14.3 degree). 3) The output errors by the three calibration methods using logistic curves were calculated. The output errors for 2-point method (calibrated by the data of minimum and maximum angles) and 3-point method (calibrated by the data of minimum, medium and maximum angles) were 1.34 and 1.22 times larger than the output errors (0.139 V) for all-point method (calibrated by all measured data), respectively.

２次元最小２乗逐次３点法による平面形状誤差の測定

A study is presented of measuring method for flat form errors by 2D least square serial 3point method. This method is extensively improved on a serial 3point method. Consequently, this approach can compensate the measuring errors which are caused by fluctuations of 9 displacement sensors implemented on a measuring head. Here, the measuring errors in this case are parallel motion errors and rotatory motion errors of the head. Furthermore, accidental errors which are involved in the measuring values are reduced by least square method. In experimental analysis, a laser interferometer is used as the measuring head. And the influence of form errors of reference surface are removed by calculating data. In this paper the following results are revealed by some simulations and several experiments. (a) The repeatability of this experiment is about 40nm (2σ). (b) Measuring values of this method sufficiently coincide with those obtained by 2D least square serial 2point method.

Serological assessment of chlamydial infection in the koala by a slide EIA technique

A rapid and simplified slide enzyme immunosorbent assay (EIA) was developed for the diagnosis of chlamydial infection in the koala. HeLa 229 cells infected with koala strain Chlamydia psittaci were fixed on the surface of multiwell slides and used as the antigen. The assay consisted of first reacting koala antiserum with the fixed C psittaci antigen, followed by reaction with biotinylated rabbit anti-koala IgG, ABC reagent and substrate. The chlamydial EIA antibody titres obtained were compared with those of a complement fixation (CF) test using koala strain C psittaci as antigen. Of 35 koala sera tested, 16 CF positive sera (greater than or equal to 1:8) also had a positive titre (greater than or equal to 1:200) in the slide EIA test (sensitivity 93.8%, 15/16). Nineteen CF negative sera were also negative in the slide EIA (specificity 100%, 19/19). Sixty-eight samples of koala blood were collected by ear-prick using a sampling paper method and were assayed by both tests. Sensitivity of the slide EIA was 100% (15/15) and specificity of the test was 96.2% (51/53). To simplify the slide EIA for use as a practical screening test, a 3-point serum dilution series (1:100, 1:200, 1:400) was used. This 3-point slide EIA was compared with the CF test using sheep strain chlamydial antigen. Thirty-nine sera were assayed by both tests. The sensitivity of the 3-point method was 85.7% (6/7) and the specificity was 71.9% (23/32) as compared with the sheep antigen CF test.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic evaluation of porcine bioprostheses in the mitral position by doppler echocardiography

Twenty-four patients with porcine bioprostheses in the mitral position were studied by Doppler echocardiography followed by cardiac catheterization within 24 hours. Doppler mean diastolic mitral valve gradient was calculated by a 3-point method and mitral valve area was determined by the pressure half-time method. Data from Doppler echocardiography and cardiac catheterization were compared. There was a strong correlation between Doppler echocardiography and catheterization-determined mean diastolic gradient: r = 0.9, standard error of estimate (SEE) = 1.4 mm/Hg (regression equation y = 0.63x + 1.41), p <0.001. There was also a strong correlation between Doppler echocardiography and catheterization-determined mitral valve area: r = 0.86, SEE = 0.18 cm 2 (regression equation y = 0.64x + 0.52), p <0.001. Fourteen patients whose valvular function was considered normal by clinical evaluation had Doppler-calculated mean diastolic gradients of 4.5 to 9.5 mm Hg (mean 6.5 ± 1.4); the Doppler-determined valve area was 1.15 to 2.0 cm 2 (mean 1.54 ± 0.3). Ten patients had a malfunctioning bioprosthesis, 7 had severe mitral regurgitation and 3 had stenosis. Valvular malfunction in all 10 patients was detected by Doppler echocardiography and confirmed by catheterization and angiocardiography. Nine patients underwent reoperation. Doppler hemodynamic evaluation of porcine bioprostheses in the mitral position provided noninvasive information comparable to that obtained by cardiac catheterization.

A computer-assisted morphometric analysis of the organ of Corti.

This paper describes a method for a computer-assisted morphometric analysis of the organ of Corti and presents normal morphometric data on the chinchilla cochlea. The computer-assisted light microscope system that we developed consists of commercially available equipment: an Olympus light microscope, Boeckler X, Y motorized stage micrometers, an IBM PC computer and a computer program written by the second author. The system was developed for the analysis of whole-mount, surface preparations of the organ of Corti. The procedure for producing suitable surface preparations for a computer-assisted analysis of hair cells was described in a previous paper (Santi, 1986). The analysis procedure requires 2 passes along the length of the basilar membrane. During the first pass, the system establishes an X, Y slide coordinate system and maps basilar membrane distance onto the coordinate system. This procedure was performed in approximately 10 min using an efficient, 3-point arc approximation method. During the second pass, the user scans along the length of the basilar membrane and measures organ of Corti structures (e.g., hair cell dimensions) or records abnormal or missing hair cells. In addition to providing distance along the length of the basilar membrane, the system could also determine which hair cell row the user was examining. Thus, recording damaged and missing hair cells consisted of merely pressing the appropriate footpedal to indicate the type and degree of hair cell damage. After assessing hair cell damage, a cytocochleogram with an accompanying table of descriptive statistics was produced. Since the X,Y coordinate system for each slide was stored on a disk along with its corresponding basilar membrane distance map, slides could be removed and later reevaluated without the loss of previously obtained data. Normal morphometric data on the chinchilla organ of Corti consisted of cell dimensions within the reticular lamina and a two-dimensional graphical reconstruction of the curvature of the basilar membrane.

工作機械上での3点法円筒度測定に関する研究 (第1報)

A new method is developed for in situ measurement of cylindricity by employing an extended principle of the 3-point roundness measurement. Different from the measurement performed on a dedicated measuring instrument, the workpiece form error is measured right on the working position by utilizing the spindle rotation and feed motion of the machine tool. In the present paper, described is a method by which the measurements by the 3-point method are processed by digital calculation technique so as to eliminate the substantial rotating error of the spindle and straightness error of the feed motion. Measurements of the cylindrical form error by the 3-point method and those by the radius method are conducted to verify this 3-point method. The results exhibit fairly good agreement of the measured diameter deviation, out-of-roundness error the curvature of axis and cylindricity error by the 3-point method with those measured by the radius method.

Efficiencies of Microwave 2-Ports from Reflection Coefficient Measurements (Short papers)

It is well-known that one can determine the efficiency of a microwave 2-port by measuring the reflection coefficient /splGamma//sub 1/ at the input port when the output port is terminated by a sliding short circuit. The locus of /spl Gamma//sub 1/ is a circle whose radius equals the efficiency /spl eta//sub 2m/ for energy entering port 2 when port 1 is terminated in a nonreflecting load. Similarly /spl eta//sub 1m/ is the radius of the circle when port is terminated in a sliding short circuit. This note describes a procedure for obtaining, from the same measured data, new reflection coefficients /spl Gamma//sub 1N/ and /spl Gamma//sub 2N/, whose circular loci have radii R/sub 1N/ and R/sub 2N/ which give the efficiencies of the 2-port when connected to an arbitrary load of reflection coefficient /spl Gamma//sub L/. Thus the /spl Gamma//sub 1/ or /spl Gamma//sub 2/ data may be used to obtain the efficiency of the 2-port when terminated in any arbitrary load. The method is potentially more accurate than the 3-point method since errors can be reduced by drawing a circle through many measured points.

Effective Wave Lengths

There is no known method of designating and measuring the quality of mixed radiation beams which does not depend on the material employed for its determination. The effective wave length idea of Duane (1) should hypothetically give effective wave lengths which are the same for a limited group of metals. When experimentally tested, however, each metal gives effective wave lengths which differ greatly from those obtained with the same radiations but with different metals (2). Naturally this leaves no hope that measurements made with a certain convenient measuring metal can be easily transposed and interpreted in terms of measurements made with another metal, in water, or in body tissues. Therefore, any hope of arriving at a definite and clear-cut meaning of so-called tissue effects or tissue doses is frustrated. A so-called 3-point method (3) gives an absorption and a heterogeneity coefficient (µ and η), the first indicating the penetrative power of a mixed radiation beam as it enters the exposed material a...

Vincent’s Infection: Microscopic Diagnosis

Porcelain fused to zirconia prostheses are widely used, but porcelain chipping, fracture, spalling and delamination are common clinical problems. Conventional bond strength testing is inherently unsuited for studying interfacial failure by cracking in brittle materials. Instead, fracture toughness is a more meaningful parameter because it can assess the robustness of the interface when subjected to loading, but fracture mechanics approaches have only rarely been used. Our purpose was to develop a novel, simple, 3-point flexural methodology and mathematical analysis to measure the fracture toughness of the porcelain to zirconia interface.Equations were derived to estimate the fracture toughness of the bond by computing the interfacial energy release rate for a novel simple 3-point flexural test model. The test was validated using two different configurations of layered zirconia/porcelain beams (n = 10), approximating the dimensions of a fixed dental prosthesis, fabricated from a tetragonal polycrystalline zirconium dioxide partially stabilized with yttria and a feldspathic dental porcelain.Cracking along the bimaterial interface was produced and measured as a discrete event. Fracture toughness means (standard deviations) computed from the measured energy release rate, for the porcelain to zirconia interface in two different specimen configurations were 7.9 (1.3) and 5.3 (1.6) J/m2.Equations were derived to measure interfacial fracture toughness of brittle materials using a novel simple 3-point flexural test method. The test was then validated; estimates for the fracture toughness for the porcelain to zirconia bond, overlapped with previously published data derived from more complex 4-point notched tests.

The testing of transformers and transformer iron

1. Introduction. 2. Regulation diagram. 3. Diagram of voltage characteristic. 4. The short-circuit test. 5. Proposed standard transformer test. 6. The 3-point wattmeter method. 7. Standard tests for-(a) core losses: separation by constant-frequency test ; (b) copper losses; (c) efficiency; (d) heating ; (e) regulation. 8. The auxiliary transformer. 9. Special tests-(a) by means of extra turns ; (b) at half power factor; (c) out-of-phase test; (d) 3-phase transformers. 10. Hysteresis by slow cyclic change-(a) method of constant induced voltage ; (b) theory; (c) application to testing of small samples. 11. Conclusion.