Probe Calibration Research Articles

Towards a traceable probe calibration method for white light interference based AFM

Probe calibration is the basis of accurate atomic force microscope (AFM) measurement. In white light interference based AFM (WLI-AFM), the relationship between the vertical displacement of probe and the position of the interference fringes on probe cantilever should be calibrated for accurate measurement. In this paper, a traceable probe calibration method for WLI-AFM is proposed. A high resolution displacement measurement system based on laser interference is constructed to obtain the vertical displacement of probe with high accuracy. This system is used for standard displacement input for calibration and makes the measurement result traceable to optical wavelength. A zero-order fringe positioning algorithm is presented to determine the position of the interference fringes on probe cantilever. A probe deflection model is established for the calibration relationship which is continuous and can be used for measurement. While calibration is conducted, series of zero-order fringe positions are obtained corresponding to the probe displacement inputs. The data are processed by the probe deflection model to obtain the calibration relationship. The proposed method is applied in a self-developed WLI-AFM. It is verified that the accuracy of the method is higher than the previous methods by certain experiments on this WLI-AFM.

Calibration and comparison of thermal dissipation, heat ratio and heat field deformation sap flow probes for diffuse-porous trees

Sap flow probes are routinely used in forest and horticulture hydrology for estimating tree water use. This requires unbiased measurements when upscaling from tree to stand level, but accuracy and comparability of different thermometric methods have been questioned. Three sap flow measuring techniques were compared against gravimetric flow measurement in cut stem segments: ‘Granier-type’ thermal dissipation probes (TDP; three different sensor types), the heat field deformation method (HFD), and the heat ratio method (HRM). For the empirical methods (TDP and HFD), new calibration parameters were estimated using a nonlinear hierarchical modelling approach. 66 stem segments from five temperate, diffuse-porous tree species (9–16cm stem diameter, 100cm stem length) were exposed to a wide range of flux densities by applying subatmospheric pressure (−50 to −650hPa) analogous to natural flow conditions in the field.All TDP probes underestimated flux density by 23–45% when calculated with Granier's original calibration parameters, with the deviation increasing with flux rate. The accuracy was significantly improved by estimating new calibration parameters, especially for probes differing from Granier's original sensor design. Species-specific parameters further improved accuracy, although the species differences might partially be explained by variation in the observed ranges of sap flux. The HFD sensor overestimated gravimetric flow by ∼11%; empirical calibration did not improve its accuracy compared to the manufacturer's equation. At low to medium flow rates, the HRM system achieved higher accuracy than the other probes (0.8% underestimation), while performing poorly at high flux rates under our measurement settings (energy input of 25J). Both for TDP and HFD sensors, we observed a surprisingly large variability in calibration parameters between different stems of the same species.We conclude that (i) TDP and HFD sensors require species-specific calibration to measure sap flux with high accuracy, (ii) the original Granier equation cannot be used for TDP probes with deviating design, and (iii), at low to medium flow rates, the highest accuracy can be achieved with HRM sensors. Our results help to increase the accuracy of tree sap flow measurements with thermal dissipation probes, and to assess various levels of errors related to the different thermometric methods. This is important when synthesizing forest transpiration data on regional and global scales.

Integrated cosmological probes: Extended analysis

Recent progress in cosmology has relied on combining different cosmological probes. In earlier work, we implemented an integrated approach to cosmology where the probes are combined into a common framework at the map level. This has the advantage of taking full account of the correlations between the different probes, to provide a stringent test of systematics and of the validity of the cosmological model. We extend this analysis to include not only CMB temperature, galaxy clustering, weak lensing from SDSS but also CMB lensing, weak lensing from the DES SV survey, Type Ia SNe and $H_{0}$ measurements. This yields 12 auto- and cross-power spectra as well as background probes. Furthermore, we extend the treatment of systematic uncertainties. For $\Lambda$CDM, we find results that are consistent with our earlier work. Given our enlarged data set and systematics treatment, this confirms the robustness of our analysis and results. Furthermore, we find that our best-fit cosmological model gives a good fit to the data we consider with no signs of tensions within our analysis. We also find our constraints to be consistent with those found by WMAP9, SPT and ACT and the KiDS weak lensing survey. Comparing with the Planck Collaboration results, we see a broad agreement, but there are indications of a tension from the marginalized constraints in most pairs of cosmological parameters. Since our analysis includes CMB temperature Planck data at $10 < \ell < 610$, the tension appears to arise between the Planck high$-\ell$ and the other measurements. Furthermore, we find the constraints on the probe calibration parameters to be in agreement with expectations, showing that the data sets are mutually consistent. In particular, this yields a confirmation of the amplitude calibration of the weak lensing measurements from SDSS, DES SV and Planck CMB lensing from our integrated analysis. [abridged]

Contactless Radio Frequency Monitoring of Dielectric Properties of Egg White During Gelation

The evaluation of dielectric properties in the radio frequency (RF) bandwidth is highly relevant to characterize the physical or physiological state of organic materials. This paper reports on the implementation of an easy-to-use and contactless RF dielectric sensing technique used for the monitoring of the heat-induced gelation of a white egg sample. The sensing technique basically consists in the distant monitoring of a high-quality factor inductive RF resonator operating at 98 MHz, which is electromagnetically coupled to the egg white sample. A lumped element modeling of the contactless RF probe interacting with the egg white is proposed. It is used to estimate both the conductivity and the permittivity of the sample during its gelation, starting from the impedance changes measured at the ends of the RF probe, and after probe calibration carried out using a reference NaCl solution. The results obtained during a 10 h monitoring experience allow the dynamics of the egg white gelation to be analyzed. These results open the way to the development of easy-to-implement and non-invasive dielectric monitoring of organic materials, with many prospects in agrifood as well as health monitoring applications.

Non-Ideal Compressible-Fluid Dynamics of Fast-Response Pressure Probes for Unsteady Flow Measurements in Turbomachinery

The dynamic response of pressure probes for unsteady flow measurements in turbomachinery is investigated numerically for fluids operating in non-ideal thermodynamic conditions, which are relevant for e.g. Organic Rankine Cycles (ORC) and super-critical CO2 applications. The step response of a fast-response pressure probe is investigated numerically in order to assess the expected time response when operating in the non-ideal fluid regime. Numerical simulations are carried out exploiting the Non-Ideal Compressible Fluid-Dynamics (NICFD) solver embedded in the open-source fluid dynamics code SU2. The computational framework is assessed against available experimental data for air in dilute conditions. Then, polytropic ideal gas (PIG), i.e. constant specific heats, and Peng-Robinson Stryjek-Vera (PRSV) models are applied to simulate the flow field within the probe operating with siloxane fluid octamethyltrisiloxane (MDM). The step responses are found to depend mainly on the speed of sound of the working fluid, indicating that molecular complexity plays a major role in determining the promptness of the measurement devices. According to the PRSV model, non-ideal effects can increase the step response time with respect to the acoustic theory predictions. The fundamental derivative of gas-dynamic is confirmed to be the driving parameter for evaluating non-ideal thermodynamic effects related to the dynamic calibration of fast-response aerodynamic pressure probes.

Gastric acid secretion and gastrin release during continuous vagal neuromonitoring in thyroid surgery.

The vagus nerve (VN) has essential regulatory roles in the gastric acid secretion and gastrin release. Continuous intraoperative neuromonitoring (CIONM) via VN stimulation is a promising technique in thyroid surgery because it potentially avoids injury to the recurrent laryngeal nerve. However, no studies have investigated changes in gastric acid secretion and gastrin release during CIONM. This prospective study of 58 thyroid surgery patients compared gastric acid and serum gastrin at five time points: (1) before skin incision, (2) after baseline calibration of CIONM probe, (3) +20min from baseline, (4) before probe removal, and (5) after extubation. Patients were excluded if they had any history of using tobacco, acid suppression medications, or drugs that affect gastric motility. Patients were also excluded if they had any history of gastroesophageal reflux symptoms, gastroesophageal reflux disease, peptic ulcer disease, helicobacter pylori infection, or chronic kidney disease. Non significant differences in mean gastric pH values were observed at all time points, i.e., (1) before skin incision (2.2±0.2; p=0.50), (2) after baseline calibration of CIONM probe (2.0±0.8; p=0.62), (3) +20min from baseline (2.5±0.5; p=0.24), (4) before probe removal (2.9±0.9; p=0.52), and (5) after extubation (2.6±1.0; p=0.60). Comparisons of pH monitoring parameters revealed no significant differences in age, gender, side of CIONM (left vs. right), sequence of CIONM, or duration of CIONM. Gastrin values were normal in sequential determinations and did not significantly differ at any time points. CIONM performed via VN stimulation during total thyroidectomy in healthy patients does not influence gastrin secretion and gastric pH.

The Oxford Probe: an open access five-hole probe for aerodynamic measurements

The Oxford Probe is an open access five-hole probe designed for experimental aerodynamic measurements. The open access probe can be manufactured by the end user via additive manufacturing (metal or plastic). The probe geometry, drawings, calibration maps, and software are available under a creative commons license. The purpose is to widen access to aerodynamic measurement techniques in education and research environments. There are many situations in which the open access probe will allow results of comparable accuracy to a well-calibrated commercial probe. We discuss the applications and limitations of the probe, and compare the calibration maps for 16 probes manufactured in different materials and at different scales, but with the same geometrical design.

A method for soil moisture probes calibration and validation of satellite estimates

Optimization of field techniques is crucial to ensure high quality soil moisture data. The aim of the work is to present a sampling method for undisturbed soil and soil water content to calibrated soil moisture probes, in a context of the SMOS (Soil Moisture and Ocean Salinity) mission MIRAS Level 2 soil moisture product validation in Pampean Region of Argentina. The method avoids soil alteration and is recommended to calibrated probes based on soil type under a freely drying process at ambient temperature. A detailed explanation of field and laboratory procedures to obtain reference soil moisture is shown. The calibration results reflected accurate operation for the Delta-T thetaProbe ML2x probes in most of analyzed cases (RMSE and bias≤0.05m3/m3). Post-calibration results indicated that the accuracy improves significantly applying the adjustments of the calibration based on soil types (RMSE≤0.022m3/m3, bias≤−0.010m3/m3).•A sampling method that provides high quality data of soil water content for calibration of probes is described.•Importance of calibration based on soil types.•A calibration process for similar soil types could be suitable in practical terms, depending on the required accuracy level.

Design of a test facility for probe calibration

A possibility to easily calibrate probes for flow field measurements is always welcome. From this reason, a design of a test facility for probe calibration was made. The probes will be calibrated in a free jet of known properties, which is created by an exchangeable nozzle to cover a wide range of Mach numbers up to Mach 2. The most important is to create a homogeneous flow across the test section. This is accomplished by a precise design of the nozzles carried out by numerical tools. The convergent nozzle part is common for all subsonic flow regimes while the divergent part (forming a de Laval nozzle) is suited for a specific supersonic Mach number. These parts are designed using the method of characteristics. Numerical simulations performed by a CFD code show a feasibility and quality of the proposed test facility.

ITER-like antenna capacitors voltage probes: Circuit/electromagnetic calculations and calibrations.

The analyses illustrated in this manuscript have been performed in order to provide the required data for the amplitude-and-phase calibration of the D-dot voltage probes used in the ITER-like antenna at the Joint European Torus tokamak. Their equivalent electrical circuit has been extracted and analyzed, and it has been compared to the one of voltage probes installed in simple transmission lines. A radio-frequency calibration technique has been formulated and exact mathematical relations have been derived. This technique mixes in an elegant fashion data extracted from measurements and numerical calculations to retrieve the calibration factors. The latter have been compared to previous calibration data with excellent agreement proving the robustness of the proposed radio-frequency calibration technique. In particular, it has been stressed that it is crucial to take into account environmental parasitic effects. A low-frequency calibration technique has been in addition formulated and analyzed in depth. The equivalence between the radio-frequency and low-frequency techniques has been rigorously demonstrated. The radio-frequency calibration technique is preferable in the case of the ITER-like antenna due to uncertainties on the characteristics of the cables connected at the inputs of the voltage probes. A method to extract the effect of a mismatched data acquisition system has been derived for both calibration techniques. Finally it has been outlined that in the case of the ITER-like antenna voltage probes can be in addition used to monitor the currents at the inputs of the antenna.

First In-Core Simultaneous Measurements of Nuclear Heating and Thermal Neutron Flux Obtained With the Innovative Mobile Calorimeter CALMOS Inside the OSIRIS Reactor

Nuclear heating inside a MTR reactor has to be known in order to design and run irradiation experiments which have to fulfill target temperature constraints. This measurement is usually carried out by calorimetry. The innovative calorimetric system, CALMOS, has been studied and built in 2011 for the 70MWth OSIRIS reactor operated by CEA. Thanks to a new type of calorimetric probe, associated to a specific displacement system, it provides measurements along the fissile height and above the core. Calorimeter working modes, measurement procedures, main modeling and experimental results and expected advantages of this new technique have been already presented in previous papers. However, these first in-core measurements were not performed beyond $6~\mathrm {W} \cdot \mathrm {g} ^{-1}$ , due to an inside temperature limitation imposed by a safety authority requirement. In this paper, we present the first in-core simultaneous measurements of nuclear heating and conventional thermal neutron flux obtained by the CALMOS device at 70 MW nominal reactor power. For the first time, this experimental system was operated in nominal in-core conditions, with nominal neutron flux up to 2.7 $10 ^{14} ~\mathrm {n}\cdot \mathrm {cm}^{-2} \cdot \mathrm {s} ^{-1}$ and nuclear heating up to $12~\mathrm {W} \cdot \mathrm {g} ^{-1}$ . After a brief reminder of the calorimetric cell configuration and displacement system specificities, first nuclear heating distributions at nominal power are presented and discussed. In order to reinforce the heating evaluation, a comparison is made between results obtained by the probe calibration coefficient and the zero methods. Thermal neutron flux evaluation from SPND signal processing required a specific TRIPOLI-4 Monte Carlo calculation which has been performed with the precise CALMOS cell geometry. In addition, the Finite Element model for temperatures map prediction inside the calorimetric cell has been upgraded with recent experimental data obtained up to $12~\mathrm {W} \cdot \mathrm {g} ^{-1}$ . Finally, the experience feedback led us to improvement perspectives. A second device is currently under manufacturing and main technical options are presented.

IBIS: an OR ready open-source platform for image-guided neurosurgery.

Navigation systems commonly used in neurosurgery suffer from two main drawbacks: (1) their accuracy degrades over the course of the operation and (2) they require the surgeon to mentally map images from the monitor to the patient. In this paper, we introduce the Intraoperative Brain Imaging System (IBIS), an open-source image-guided neurosurgery research platform that implements a novel workflow where navigation accuracy is improved using tracked intraoperative ultrasound (iUS) and the visualization of navigation information is facilitated through the use of augmented reality (AR). The IBIS platform allows a surgeon to capture tracked iUS images and use them to automatically update preoperative patient models and plans through fast GPU-based reconstruction and registration methods. Navigation, resection and iUS-based brain shift correction can all be performed using an AR view. IBIS has an intuitive graphical user interface for the calibration of a US probe, a surgical pointer as well as video devices used for AR (e.g., a surgical microscope). The components of IBIS have been validated in the laboratory and evaluated in the operating room. Image-to-patient registration accuracy is on the order of [Formula: see text] and can be improved with iUS to a median target registration error of 2.54 mm. The accuracy of the US probe calibration is between 0.49 and 0.82 mm. The average reprojection error of the AR system is [Formula: see text]. The system has been used in the operating room for various types of surgery, including brain tumor resection, vascular neurosurgery, spine surgery and DBS electrode implantation. The IBIS platform is a validated system that allows researchers to quickly bring the results of their work into the operating room for evaluation. It is the first open-source navigation system to provide a complete solution for AR visualization.

Individualized dosimetry for patients with graves’ disease

Introduction Following Directive 2013/59 Euratom, all therapeutic exposures of target volumes shall be individually planned and their delivery appropriately verified. We have developed a home-made software for I-131 dosimetry in hyperthyroid patients using gammacamera and capture probe for prior and post treatment. Purpose This study describes the dosimetry method, the differences between pre and post treatment purposes, and compare its results. Materials and methods We base our procedure on the EANM Dosimetry Committee Guidelines using an INa Probe for uptake measurements at 2, 24 and 96 h after administration of 25 μCi tracer activity (also measured before its administration) and two Tc-99m planar images to estimate the thyroid mass. A two compartimental model is used to calculate the required activity to achieve 160 Gy to the target. Two uptake measurements are acquired at 96 and 168 h post-treatment to calculate the real absorbed dose to the thyroid, using a monocompartimental model and dead time correction for saturation effect through a previous probe calibration curve. 78 patients treated during 2015 have been analyzed. Results 163,1 Gy and 37,7 Gy are the average and standard deviation of administered absorbed doses, ranging from 87,3 Gy to 240,1 Gy. The mean activity to be administered according the used model is 9,1 mCi which differs from previously used (Marinelli algorithm, 7,3 mCi) and administered (8,9 mCi). Differences of means between activities by Marinelli and by our method using t-Student are significant (p Conclusion Individualized pre and post treatment dosimetry for hyperthyroidism I-131 therapy is mandatory.

Absolute calibration of sniffer probes on Wendelstein 7-X.

Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m(2) per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m(2) per MW injected beam power is measured.

3D-calibration of three- and four-sensor hot-film probes based on collocated sonic using neural networks

High resolution measurements of turbulence in the atmospheric boundary layer (ABL) are critical to the understanding of physical processes and parameterization of important quantities, such as the turbulent kinetic energy dissipation. Low spatio-temporal resolution of standard atmospheric instruments, sonic anemometers and LIDARs, limits their suitability for fine-scale measurements of ABL. The use of miniature hot-films is an alternative technique, although such probes require frequent calibration, which is logistically untenable in field setups. Accurate and truthful calibration is crucial for the multi-hot-films applications in atmospheric studies, because the ability to conduct calibration in situ ultimately determines the turbulence measurements quality. Kit et al ( J. Atmos. Ocean. Technol. 27 23–41) described a novel methodology for calibration of hot-film probes using a collocated sonic anemometer combined with a neural network (NN) approach. An important step in the algorithm is the generation of a calibration set for NN training by an appropriate low-pass filtering of the high resolution voltages, measured by the hot-film-sensors and low resolution velocities acquired by the sonic. In Kit et al ( J. Atmos. Ocean. Technol. 27 23–41), Kit and Grits ( J. Atmos. Ocean. Technol. 28 104–10) and Vitkin et al ( Meas. Sci. Technol. 25 75801), the authors reported on successful use of this approach for in situ calibration, but also on the method’s limitations and restricted range of applicability. In their earlier work, a jet facility and a probe, comprised of two orthogonal x-hot-films, were used for calibration and for full dataset generation. In the current work, a comprehensive laboratory study of 3D-calibration of two multi-hot-film probes (triple- and four-sensor) using a grid flow was conducted. The probes were embedded in a collocated sonic, and their relative pitch and yaw orientation to the mean flow was changed by means of motorized traverses. The study demonstrated that NN-calibration is a powerful tool for calibration of multi-sensor 3D-hot film probes embedded in a collocated sonic, and can be employed in long-lasting field campaigns.

Phased Array Antenna Calibration with Probe Positioning Errors [Measurements Corner

Calibration is often performed inservice with a calibration probe (CP) located in the far field (FF) of the antenna under test (AUT). Nevertheless, in some cases, it is suitable to work in the near-field (NF) environment. NF calibration is especially useful for large-aperture phased-array antennas (PAAs), when it is often complicated to arrange the CP in the FF of the antenna array. Recalculating complex initial coefficients from the NF to the FF requires taking into account distances between the phase centers of the emitters of the channels under test and the phase center of the CP. In this article, the influence of errors in the determination of coordinates of a CP on the calibration results, together with antenna pattern distortions, are considered. The derived formulas could be used to produce new requirements on the accuracy of an AUT in a CP survey.

Calibration of a non-invasive cosmic-ray probe for wide area snow water equivalent measurement

Abstract. Measuring snow water equivalent (SWE) is important for many hydrological purposes such as modelling and flood forecasting. Measurements of SWE are also crucial for agricultural production in areas where snowmelt runoff dominates spring soil water recharge. Typical methods for measuring SWE include point measurements (snow tubes) and large-scale measurements (remote sensing). We explored the potential of using the cosmic-ray soil moisture probe (CRP) to measure average SWE at a spatial scale between those provided by snow tubes and remote sensing. The CRP measures above-ground moderated neutron intensity within a radius of approximately 300 m. Using snow tubes, surveys were performed over two winters (2013/2014 and 2014/2015) in an area surrounding a CRP in an agricultural field in Saskatoon, Saskatchewan, Canada. The raw moderated neutron intensity counts were corrected for atmospheric pressure, water vapour, and temporal variability of incoming cosmic-ray flux. The mean SWE from manually measured snow surveys was adjusted for differences in soil water storage before snowfall between both winters because the CRP reading appeared to be affected by soil water below the snowpack. The SWE from the snow surveys was negatively correlated with the CRP-measured moderated neutron intensity, giving Pearson correlation coefficients of −0.90 (2013/2014) and −0.87 (2014/2015). A linear regression performed on the manually measured SWE and moderated neutron intensity counts for 2013/2014 yielded an r2 of 0.81. Linear regression lines from the 2013/2014 and 2014/2015 manually measured SWE and moderated neutron counts were similar; thus differences in antecedent soil water storage did not appear to affect the slope of the SWE vs. neutron relationship. The regression equation obtained from 2013/2014 was used to model SWE using the moderated neutron intensity data for 2014/2015. The CRP-estimated SWE for 2014/2015 was similar to that of the snow survey, with an root-mean-square error of 8.8 mm. The CRP-estimated SWE also compared well to estimates made using snow depths at meteorological sites near (&lt; 10 km) the CRP. Overall, the empirical equation presented provides acceptable estimates of average SWE using moderated neutron intensity measurements. Using a CRP to monitor SWE is attractive because it delivers a continuous reading, can be installed in remote locations, requires minimal labour, and provides a landscape-scale measurement footprint.

A text‐meandered RFID tag implemented with conductive threads

ABSTRACTWe present a wearable RFID tag implemented on a fabric, comprising four alphabet texts embroidered by conductive threads. The tag is optimized to provide a conjugate match to the RFID chip impedance at the operation frequency, 910 MHz. Various tags with different stitching patterns and thread diameters are examined in simulation and a number of tags are measured using two‐port differential probe suitable for balanced tag structures. The measured results of tag impedance show good agreements to the simulation results with slight errors caused by imperfection in probe calibration. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1978–1984, 2016

FEM and experimental investigation of the thermal drift in ultra-high precision measuring machines for dimensional metrology

The thermal drifts induced by the power dissipated by mechanical guiding systems represent the main limitation on the accuracy of ultra-high precision cylindricity machines. Thus, a high precision compact prototype (high precision set-up) was designed such as to simulate the behaviour of a cylindricity machine and to insure in-situ calibration of capacitance probes with regards to four laser interferometers. The set-up is equipped with three heating wires simulating the power dissipated by the mechanical guiding systems and nineteen temperature Pt100 probes to monitor the temperature distribution. A time-independent and a time-dependent thermal Finite Elements Models (FEM) of the set-up were achieved, and the results were compared to experimental ones. This comparison presents a global agreement. The simulations of cylindricity measurements reveal that the thermal expansion is equivalent to few nanometres.

Guided ultrasound calibration: where, how, and how many calibration fiducials.

Many image-guided interventions rely on tracked ultrasound where the transducer is augmented with a tracking device. The relationship between the ultrasound image coordinate system and the tracking sensor must be determined accurately via probe calibration. We introduce a novel calibration framework guided by the prediction of target registration error (TRE): Between successive measurements of the calibration phantom, our framework guides the user in choosing the pose of the calibration phantom by optimizing TRE. We introduced an oriented line calibration phantom and modeled the ultrasound calibration process as a point-to-line registration problem. We then derived a spatial stiffness model of point-to-line registration for estimating TRE magnitude at any target. Assuming isotropic, identical localization error, we used the model to estimate TRE for each pixel using the current calibration estimate. We then searched through the calibration tool space to find the pose for the next fiducial which maximally minimized TRE. Both simulation and experimental results suggested that TRE decreases monotonically, reaching an asymptote when a sufficient number of measurements (typically around 12) are made. Independent point reconstruction accuracy assessment showed sub-millimeter accuracy of the calibration framework. We have introduced the first TRE-guided ultrasound calibration framework. Using a hollow straw as an oriented line phantom, we virtually constructed a rigid lines phantom and modeled the calibration process as a point-to-line registration. Highly accurate calibration was achieved with minimal measurements by using a spatial stiffness model of TRE to strategically choose the pose of the calibration phantom between successive measurements.