Contact pressure measurements in total knee replacements are often made using a discrete sensor such as the Tekscan K-Scan sensor. However, no method currently exists for predicting the magnitude of sensor discretization errors in contact force, peak pressure, average pressure, and contact area, making it difficult to evaluate the accuracy of such measurements. This study identifies a non-dimen...

[1] Most standard air temperature measurements are subject to significant errors mainly due to sensor heating by solar radiation, even when the measurement principle is accurate and precise. We present various air temperature measurements together with other measurements of meteorological parameters using different sensor systems at a snow-covered and a vegetated site. Measurements from natural...

The types of error produced by beam deviation in the optical elements of an ellipsometer are examined. It is shown that there are two types of error that may be significant-systematic errors due to a variation in the plane of incidence and in the angle of incidence at the specimen and errors due to the combined effects of beam displacement and nonuniformities in either the detector response or ...

The accuracy of methods used in Cape Town hospitals and clinics for the measurement of weight, length and age in neonates and infants became suspect during a survey of 12 local authority and 5 private sector clinics in 1994-1995 (Harrison et al. 1998). A descriptive prospective study to determine the accuracy of these methods in neonates at four maternity hospitals [2 public and 2 private] and ...

We investigate the impact of instrumental systematic errors on the potential of cosmic microwave background polarization experiments targeting primordial B-modes. To do so, we introduce spin-weighted Müller matrix-valued fields describing the linear response of the imperfect optical system and receiver, and give a careful discussion of the behaviour of the induced systematic effects under rotat...

The errors in determining the biologically effective and broadband UV irradiances from spectroradiometer measurements depend critically on procedures employed in the calibration process. A series of intercomparisons of two calibration standards and a spectroradiometer were undertaken in two laboratories. The near UV (320-400 nm) and shorter wavelength (280-320 nm) waveband irradiances of one st...

objective: cone beam computed tomography (cbct) is applied for the imaging of the maxillofacial and dental structures, particularly for surgical treatments and dental implants. the aim of this study was to assess the effect of slice thickness on the accuracy of cbct linear measurements. methods: in this diagnostic accuracy study, forty-two titanium pins with the same dimensions were inserted in...

Radar rainfall data are affected by several types of error. Beside the error in the measurement of the rainfall reflectivity and its transformation into rainfall intensity, random errors can be generated by the temporal spacing of the radar scans. The aim of this work is to analize the sensitivity of the estimated rainfall maps to the radar sampling interval, i.e. the time interval between two ...