Calibration Scheme Research Articles

Can local drain flow measurements be utilized to improve catchment scale modelling?

Tile drains constitute a shortcut from agricultural fields to surface water systems, significantly altering the transport pathways and fate of nitrate during transport. A correct representation of tile drainage flow is thus crucial for estimating nitrate load at the catchment scale and to identify optimal locations for N-mitigation measures. Drainage is a local process, controlled by local properties and drain configurations, which are rarely known for individual fields, making drainage flow and transport a challenging task in catchment scale models. This study tests the potential for improving drainage flow dynamics at catchment scale, by utilising local drainage flow measurements in a spatial calibration scheme. A distributed hydrological model, MIKE SHE, for the agricultural-dominated Norsminde catchment (145 km2) in Denmark, was calibrated using spatially distributed surrogate parameters (pilot points) to represent heterogeneity in the soil (top 3 m) and the deeper geology below 3 m. The model was calibrated using hydraulic heads, stream discharge, and measured drainage flow from eight drain catchments. Drain measurements were very important in guiding the calibration of top 3 m and subsurface pilot points located in the drainage fields, showing that drain flow hold information on both local (shallow) and regional (deeper) flow patterns. Contrarily, pilot points located outside the drained fields were mainly sensitive to the hydraulic head measurements and the summer water balance of the stream discharge on a catchment scale. Consequently, incorporation of the drain data improved local performance, but did not improve the parameterization and drain description of the entire catchment. Exploitation of the drain flow information is thus difficult beyond the drain catchments, and other approaches are needed to extrapolate and exploit the local data.

Modelling crop yield in a wheat–soybean relay intercropping system: A simple routine in capturing competition for light

Moving from sole cropping to intercropping is a transformative change in agriculture, contributing to several ecosystem services. However, modelling intercropping is challenging due to intensive parameterisation, complex calibration, and experiment scarcity. To facilitate future understanding, design and adaptation of intercropping, it is therefore necessary to develop simple modelling routines capable of simulating essential features. In this paper, we integrated a light competition module requiring four parameters into MONICA, a generic agroecosystem model, with the goal of simulating a wheat–soybean relay-row intercropping system. We tested three calibration approaches using data from two years of field experiments located in Müncheberg, Germany: sole cropping-based calibration, intercropping-based calibration and a default calibration method that incorporates both systems. Under both irrigated and rainfed conditions, MONICA successfully reproduced the aboveground biomass and yield of sole crops from field experiments, with RMSEA ranging from 0.64 t ha−1 to 2.74 t ha−1 and RMSEY ranging from 0.003 t ha−1 to 0.47 t ha−1. By taking light competition into account, the modified MONICA was able to simulate interactive performance in relay-row intercropping. Generally, MONICA overestimated the aboveground biomass and yield across the three calibration strategies, and simulations for wheat were more accurate than those for soybean. However, a comparison among the calibration strategies revealed that the intercropping-based strategy outperformed the others. It significantly improved the model efficiency for soybean yield in intercropping, increasing the Index of Agreement from 0.27 to 0.73, and it decreased the Mean Bias Error for yield by up to 76%. Our results demonstrate the feasibility of using a model that is simple in both calibration and inputs, yet detailed enough to simulate the complex aboveground light competition of intercropping. Additionally, they underscore the significance of cropping system specific calibration, highlighting the importance of calibrating crop performance specifically for intercropping in order to capture genotype-by-environment interactions.

Probing Liquid Chromatography-Tandem Mass Spectrometry Response Dynamics and Nonlinear Effects for Response Level Defined Calibration Strategies with Simple Methods To Expand Linear Dynamic Ranges.

The response characteristics of liquid chromatography-tandem mass spectrometry (LC-MS/MS) serve as the basis for selecting calibration methods in quantitative analysis. LC-MS/MS inherently exhibits nonlinear detection behavior, primarily attributed to the disproportionate growth observed between peak area and peak height at elevated response levels, potentially leading to signal saturation. This disproportionate peak growth results in reduced unit response (UR), which quantifies the instrument's detection sensitivity. LC-MS/MS typically operates within a narrow near-linear response range (NLRR) due to approximately proportional peak growth, yet the NLRR width varies across different analytes or platforms. Although the inclusion of stable isotope-labeled (SIL) internal standards (IS) in LC-MS/MS analysis can mitigate certain instrument response variations, it does not eliminate the fundamental cause of nonlinearity. Moreover, the concentration range accommodated by the NLRR can significantly fluctuate at different sensitivity levels. LC-MS/MS also encounters various other nonlinear effects, including ion suppression during ionization, signal cross-contribution between the analyte/IS, and matrix effects (ME). Consequently, quadratic regression emerges as a more adaptable approach to LC-MS/MS nonlinear response dynamics, offering a broader calibration range. The application of linear regression, on the other hand, requires strict conditions. Although the signal saturation zone typically remains inaccessible to calibration methods, reducing responses by employing less-optimal selected reaction monitoring (SRM) transitions and/or lower detection gain can facilitate fitting a wide concentration range into the NLRR, thereby enabling accurate linear regression calibration. This report delves into examining the LC-MS/MS response profile, its dynamics, and major nonlinear effects through instrument response mapping to elucidate their influence on the selection of calibration methods.

Removal of two antidepressant active pharmaceutical ingredients from hospital wastewater by polystyrene-coated magnetite nanoparticles-assisted batch adsorption process.

This study employed simple polystyrene-coated magnetite nanoparticles (PS@MNPs)-assisted batch adsorption process for the removal of two antidepressant active ingredients (amitriptyline HCl and sertraline HCl) from hospital wastewater. Dominant parameters of the adsorption process including pH, adsorbent amount, and contact period were optimized through the univariate approach to enhance the adsorption efficiency. Upon reaching optimum adsorption conditions, equilibrium experiments were performed by spiking the adsorbates in hospital wastewater in the concentration range of 100-2000 μg/L. The concentrations of the adsorbates in the effluent were calculated using the matrix-matching calibration strategy to enhance the accuracy of quantification. A validated switchable solvent-based liquid phase microextraction (SS-LPME) method was employed to enrich the two active pharmaceutical ingredients (APIs) prior to sensitive determination with GC-MS (gas chromatography-mass spectrometry). The equilibrium data were mathematically modeled employing the Langmuir and Freundlich adsorption isotherm models. The isotherm constants were calculated, and the results showed that both the isotherm models fitted well with the experimental data. The efficient and simple batch adsorption strategy reported in this study was successfully employed to remove amitriptyline HCl and sertraline HCl from hospital wastewater at low concentrations.

A reliable external calibration method for reaction monitoring with benchtop NMR.

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique with the ability to acquire both quantitative and structurally insightful data for multiple components in a test sample. This makes NMR spectroscopy a desirable tool to understand, monitor, and optimize chemical transformations. While quantitative NMR (qNMR) approaches relying on internal standards are well-established, using an absolute external calibration scheme is beneficial for reaction monitoring as resonance overlap complications from an added reference material to the sample can be avoided. Particularly, this type of qNMR technique is of interest with benchtop NMR spectrometers as the likelihood of resonance overlap is only enhanced with the lower magnetic field strengths of the used permanent magnets. The included study describes a simple yet robust methodology to determine concentration conversion factors for NMR systems using single- and multi-analyte linear regression models. This approach is leveraged to investigate a pharmaceutically relevant amide coupling batch reaction. An on-line stopped-flow (i.e., interrupted-flow or paused-flow) benchtop NMR system was used to monitor both the 1,1'-carbonyldiimidazole (CDI) promoted acid activation and the amide coupling. The results highlight how quantitative measurements in benchtop NMR systems can provide valuable information and enable analysts to make decisions in real time.

Application of traceable calibration for gaseous oxidized mercury in air

BackgroundThe current speciation methods for mercury (Hg) measurements are fraught with considerable uncertainty, from sample collection to calibration. High reactivity of gaseous oxidized Hg (GOM) species and their ultra-trace level presence makes them difficult to sample and calibrate. Given that improper calibration may lead to measurement biases, reliable and metrologically traceable calibration methods are required for accurately quantifying GOM in air. In the present study, we applied the recently developed calibration method based on non-thermal plasma oxidation of elemental Hg, to a commercially available Hg air speciation system for actual environmental measurements of GOM for the first time. ResultsHg species such as HgO, HgCl2, and HgBr2 were produced with trace amounts of reactant gases (oxygen and electrolytically produced chlorine and bromine) and the production was driven by plasma-assisted oxidation. The plasma oxidation efficiency of elemental Hg with oxygen was 98.5 ± 7.5 % (k = 2), while that for chlorine and bromine was 96.8 ± 6.9 % (k = 2) and 97.4 ± 9.6 % (k = 2), respectively. The calibration method was tested against the internal permeation (Hg0) source of the Tekran 2537B Hg analyzer on-field by loading HgO to different KCl-coated denuders using the plasma. GOM concentrations were measured using the Tekran speciation system. With internal calibration, concentrations were up to 9.1 % lower than those in plasma calibration, thereby emphasizing the importance of the calibration strategy. Measurement uncertainty (k = 2) further emphasizes this distinction. Internal calibration measurement uncertainty was 36.8 %, while plasma calibration boasted lower uncertainty at 13.8 %. SignificanceThe non-thermal plasma calibration strategy, as a unique and discrete calibration method traceable to the NIST SRM 3133 for ambient air GOM measurements, provide a higher level of confidence in the accuracy of GOM measurements with several advantages over other methods. Calibrations at extreme low concentrations (<100 pg) are possible with this method relevant to ambient air GOM concentrations.

Experimental full calibration of quantum devices in a semi-device-independent way

Semi-device-independent (SDI) methods offer a credible way to calibrate preparation and measurement devices simultaneously in quantum information processing, using only prior knowledge such as the Hilbert space dimension. To date, the SDI method is restricted to a few state paradigms, which impedes its broader applications. Recently, Tavakoli [Phys. Rev. Lett. 125, 150503 (2020)PRLTAO0031-900710.1103/PhysRevLett.125.150503] proposed an SDI scheme to certify t-designs with discrete and symmetric structures. In this work, we bridge the gap between discrete and continuous structures with a concept termed “covering angle,” while maintaining the SDI feature. This concept enables us to evaluate a quantum device’s ability to generate arbitrary quantum states in a Hilbert space via calibrating a certain t-design. This so-called full calibration method is further tailored to be tolerant of errors in realistic state production. We demonstrate this full calibration scheme for a qubit system with various t-designs and show that it renders SDI certificates for quantum key distribution, quantum random number generation, and magic state distillability.

Algorithm based Calibration Strategies in an Electric Powertrain

The latest trend in the automobile industry is electric energy usage for vehicle propulsion. The electrical energy conversion to mechanical energy via motor is the currently accepted and safe technology. The major challenge for this is the component protection strategies. Components such as the motor, battery etc. need to be protected to enhance the life cycle of the vehicle. Also, vehicle safety is of much importance to avoid any fatalities arising with regards to the mishandling of the components. This study suffices the component protection by developing algorithmbased strategies. The algorithms are pre-fed to the controller. Development of smart motor and battery is proposed via Battery Thermal management system. The energy used is of both AC as well DC form. Energy sources for the electric energy generation are different namely, Batteries, Fuel cell etc. Energy generated through chemical reaction is stored in the battery and is eventually utilized.

Novel Calibration Approach for Monitoring Aerosol Hydrogen Isotopes Using Laser-Induced Breakdown Spectroscopy for Molten Salt Reactor Off-Gas Streams.

Online monitoring is a key challenge for the continued development of molten salt reactor (MSR) technology. Laser-induced breakdown spectroscopy (LIBS) has previously been demonstrated to be a viable tool for monitoring aerosolized species and noble gases in real time, but the ability to discern varying isotopes in these streams has not yet been investigated for MSR applications. Tritium will form in MSRs from ternary fission and from (n,α)-reactions occurring in lithium-containing salts. This study compares three spectrometers of varying resolutions and types for measuring hydrogen isotope shifts in LIBS spectra of wetted filter paper. For each spectrometer, multivariate models were built (i.e., principal component regression, partial least squares regression, and multivariate curve resolution) to quantify the isotope ratio. The top models were then modified and corrected to apply the models to aerosol samples with varying isotope ratios. This novel calibration strategy offers an 82% reduction in volume of the calibration samples needed and is a more viable pathway for calibrating deployable LIBS systems. Lastly, this calibration model was compared with an all-aerosol trained model for monitoring hydrogen isotopes during a real-time test where the protium/deuterium ratio, along with representative salt species (i.e., lithium, sodium, and potassium) were adjusted dynamically. Results of this test validated the predictive capabilities of the transferred model and highlighted the capabilities of LIBS for real-time monitoring of MSR effluent streams.

Examining the transferability of height–diameter model calibration strategies across studies

Abstract Height–diameter (H–D) models are fundamental tools for predicting the relationship between tree H–D at breast height, for numerous applications in forestry. Increasingly, studies develop H–D models that can be calibrated to achieve a high level of precision with only a few observations. Different calibration methods and strategies are employed and compared in these studies, often disregarding the data used to develop the models and the H–D function used. In this study, we examined the transferability of optimal calibration strategies across studies, conducting a literature review and an empirical study. We compared the performance of six H–D functions and different calibration methods when using the same calibration strategies and dataset. Based on our literature review, we found that the most commonly employed calibration strategy is random-effects calibration and that the most common variable used to develop generalized H–D models is dominant height. We observed that different calibration methods can lead to varying results due to their different emphases on various aspects of the data and their individual limitations. Moreover, when the same dataset is used for calibration, different H–D functions may exhibit various performances. However, we found high percentages of agreement for the Curtis, Schumacher, and Wykoff H–D functions across all three calibration methods and low agreement between all functions and the Power H–D function. These observations underscore the need to consider all relevant factors, including the H–D function used, when selecting an H–D function and calibration strategy to ensure optimal transferability of the model. Our study provides insights that can improve the accuracy of H–D models, which are essential for predicting forest growth and structure in the context of changing environmental conditions.

Innovative OPA-based optical chip for enhanced digital holography.

Digital holographic imaging has emerged as a transformative technology with significant implications for AR/VR devices. However, existing techniques often suffer from limitations such as restricted field of view (FOV), high power consumption, and contrast distortion. This paper introduces an innovative optical phased array (OPA)-based chip, integrating polarization, amplitude, and phase multiplexing for enhanced complex amplitude holographic imaging. A checkerboard-style staggered array is employed in the control strategy, substantially reducing power consumption and enabling the potential for large-scale array integration. To further enhance imaging quality, we introduce what we believe are two novel calibration strategies: one is to achieve super-resolution through block imaging methods, and the other is to image using sparse aperture methods. These advancements not only provide a robust foundation for high-quality holographic imaging, but also present a new paradigm for overcoming the inherent limitations of current active holographic imaging devices. Due to challenges in chip fabrication, the research is primarily simulation-based. Nevertheless, this work presents meaningful advancements in digital holographic imaging for AR/VR applications and provides a foundation for future experimental validations.

Dual quaternion operations for rigid body motion and their application to the hand–eye calibration

The dual quaternion plays an advantageous role in the field of robotic kinematics and dynamics due to its compact expression. It is well known that quaternion can be easily implemented as algebraic operations on vectors through matrix operators. Similarly, the dual matrix operators can convert dual quaternion operations to matrix operations. However, it has not received adequate attention, and thus there are very few applications at present. With the dual matrix operators of dual quaternion, this paper re-verifies the equivalency between the conjugate formula of unit dual quaternion and dual Euler–Rodrigues formula. To combine this equivalence with the homomorphic mapping of Lie groups, a theoretical correlation of the current hand-eye calibration methods is established. Motivated by the attempt to establish a more complete scheme for hand-eye calibration, a new simultaneous method based on the conjugate formula of dual quaternion is proposed. The method verifies that the rotation problem can be extended to the rigid-body transformation problem via the dual algebra. Finally, the simulation and experimental validations for the hand–eye calibration method are given.

Model-Based Calibration and Control of Tailpipe Nitrogen Oxide Emissions in a Light-Duty Diesel Engine and Its Assessment through Model-In-The-Loop

The present paper investigates two different strategies for model-based calibration and control of tailpipe nitrogen oxide emissions in a light-duty 3.0 L diesel engine equipped with an aftertreatment system (ATS). The latter includes a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and an underfloor selective catalytic reduction (SCR) device, in which the injection of diesel exhaust fluid (DEF), marketed as ‘AdBlue’, is also taken into account. The engine was modeled in the GT-SUITE environment, and a previously developed model-based combustion controller was integrated in the model, which is capable of adjusting the start of injection of the main pulse and the total injected fuel mass, in order to achieve desired targets of engine-out nitrogen oxide emissions (NOx) and brake mean effective pressure (BMEP). First, a model-based calibration strategy consisting of the minimization of an objective function that takes into account fuel consumption and AdBlue injection was developed and assessed by exploring different weight factors. Then, a direct model-based controller of tailpipe nitrogen oxide emissions was designed, which exploits the real-time value of the SCR efficiency to define engine-out NOx emission targets for the combustion controller. Both strategies exploit the model-based combustion controller and were tested through a Model-in-the-Loop (MiL) under steady-state and transient conditions. The advantages in terms of tailpipe NOx emissions, fuel consumption, and AdBlue injection were finally discussed.

Direct Determination of Ca, K, and Mg in Soy Leaf Samples Using Laser-Induced Breakdown Spectroscopy.

This study was dedicated to developing analytical methods for determining macronutrients (Ca, K, and Mg) in soy leaf samples with and without petioles. The study's primary purpose was to present Laser-induced breakdown spectroscopy (LIBS) as a viable alternative for directly analyzing leaf samples using chemometric tools to interpret the data obtained. The instrumental condition chosen for LIBS was 70 mJ of laser pulse energy, 1.0 µs of delay time, and 100 µm of spot size, which was applied to 896 samples: 305 of soy without petioles and 591 of soy with petioles. The reference values of the analytes for the proposition of calibration models were obtained using inductively coupled plasma optical emission spectroscopy (ICP-OES) technique. Twelve normalization modes and two calibration strategies were tested to minimize signal variations and sample matrix microheterogeneity. The following were studied: multivariate calibration using partial least squares and univariate calibration using the area and height of several selected emission lines. The notable normalization mode for most models was the Euclidean norm. No analyte showed promising results for univariate calibrations. Micronutrients, P and S, were also tested, and no multivariate models presented satisfactory results. The models obtained for Ca, K, and Mg showed good results. The standard error of calibration ranged from 2.3 g/kg for Ca in soy leaves without petioles with two latent variables to 5.0 g/kg for K in soy leaves with petioles with two latent variables.

Calibrating nonlinearity coefficients of a nano-g accelerometer by dual-frequency excitation on a shaker

Nano-g accelerometers are utilized extensively in high precision applications, such as gravity measurements on moving bases, which often face strong motion disturbances. Accurately-calibrated coefficients are crucial for suppressing their high-order error effects, but challenging to measure using conventional calibration methods. This paper presents an investigation into calibration of the nonlinearity coefficient of nano-g accelerometers on a horizontal shaker driven by a dual frequency signal. A nonlinear output component occurring at the low difference frequency, with a high signal-to-noise ratio, is utilized. The calibration principle and strategy are investigated, along with an analysis of the potential experimental error sources. Two critical accompanying systematical errors, arising from shaker’s movement distortion along the primary vibration direction and gravity coupling of input acceleration caused by the guide rail deflection, are identified and eliminated through a proposed procedure. Experimental tests demonstrate an uncertainty level two orders of magnitude better than the traditional method based on the dividing head.

Dilute-and-shoot ICPMS quantification of V, Ni, Co, Cu, Zn, As, Se, Ag, Cd, Ba, and Pb in fruit juices based on matrix overcompensation calibration.

Analysis of V, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Ba, and Pb in fruit juices was performed by inductively coupled plasma mass spectrometry (ICPMS) after simple 50-fold dilution in 1% (v/v) HNO3-0.5% (v/v) HCl-5% (v/v) ethanol. Ethanol was added to overwhelm native organic components and dominate matrix effects. A universal calibration curve was built based on a likewise treated reagent standard series. This new matrix overcompensation calibration (MOC) strategy was developed to effectively compensated formatrix effects of carbon origin and achieved quantitative (92.5-118.8%) recoveries comparable to those by standard addition calibration (92.1-117.8%) and microwave-aided digestion (99.3-116.8%). The LODs were 0.528, 0.204, 0.195, and 2.07ngmL-1 for toxic elements As, Cd, Pb, and Ni, respectively, adequate for their regulatory monitoring. Ge, Rh, Tb, and Ir were used as internal standards. MOC renders a calibration curve universally applicable to any clear fruit juices of diversified crop, geographic, and manufacturer origins resulting in cost saving and enhanced productivity.

Remote Sensing of Aerosols and Water-Leaving Radiance from Chinese FY-3/MERSI Based on a Simultaneous Method

In this paper, a new simultaneous retrieval method of the SIRAW algorithm is introduced and carried out on FY3D/MERSI-II satellite images to obtain the aerosol optical thickness (AOT) and normalized water-leaving radiance (WLR) over the ocean. In order to improve the operation efficiency of SIRAW, a machine learning solver is developed to improve the speed of forward radiative transfer computation during retrieval. Ground-based measurement data from AERONET-OC and satellite products from VIIRS are used for comparative verification. The results show that the retrieved AOT and WLR from SIRAW are both in good agreement with those of AERONET-OC and VIIRS. Further, considering the degradation of the MERSI sensor, a new calibration scheme on 412 nm and 443 nm is adopted and an evaluation is carried out. Inter-comparison of derived WLR between MERSI and VIIRS indicates that the new calibration scheme could effectively improve the WLR retrieval accuracy of MERSI with better consistency to the official data of VIIRS. Therefore, this paper confirms that a simultaneous retrieval scheme combined with effective calibration coefficients can be used for high-precision retrieval of real aerosol and water-leaving radiation.

Comparison of calibration strategies for accurate quantitation by isotope dilution mass spectrometry: a case study of ochratoxin A in flour

Analysis of low-level organic contaminants in complex matrices is essential for monitoring global food safety. However, balancing sample throughput with complex experimental designs and/or sample clean-up to best reduce matrix effects is a constant challenge. Multiple strategies exist to mitigate these effects, with internal standard-based methods such as isotope dilution mass spectrometry (IDMS) being the most advantageous. Here, multiple internal calibration strategies were investigated for the quantification of ochratoxin A (OTA) in wheat samples by liquid chromatography-mass spectrometry (LC-MS). Internal standard-based quantitation methods such as single (ID1MS), double (ID2MS), and quintuple (ID5MS) isotope dilution mass spectrometry, as well as external standard calibration, were explored and compared. A certified reference material (CRM) of OTA in flour, MYCO-1, was used to evaluate the accuracy of each method. External calibration generated results 18–38% lower than the certified value for MYCO-1, largely due to matrix suppression effects. Concurrently, consistently lower OTA mass fractions were obtained for the wheat samples upon quantitation by external calibration as opposed to ID1MS, ID2MS, and ID5MS. All isotope dilution methods produced results that fell within the expected range for MYCO-1 (3.17–4.93 µg/kg), validating their accuracy. However, an average 6% decrease in the OTA mass fraction was observed from results obtained by ID1MS compared to those by ID2MS and ID5MS. Upon scrutiny, these differences were attributed to an isotopic enrichment bias in the isotopically labelled internal standard [13C6]-OTA that was used for ID1MS, the OTAL-1 CRM. The advantages and limitations of each isotopic method are illustrated.

Determination of copper in rose tea samples using flame atomic absorption spectrometry after emulsification liquid–liquid microextraction

Rose tea infusion has gained popularity worldwide due to its health benefits. However, it is known that tea plants can be contaminated with heavy metals including copper. Hence, an accurate and applicable analytical method namely emulsification liquid–liquid microextraction based deep eutectic solvent – flame atomic absorption spectrometry (ELLME-DES-FAAS) was proposed to determine copper at trace levels in rose tea samples. Under the optimum experimental conditions, analytical figures of merit for the developed method were examined, and dynamic range, limit of detection (LOD) and limit of quantification (LOQ) were found to be 5.07–246.61 µg/kg (mass-based) with 0.9992 coefficient of determination, 2.50 µg/kg and 8.32 µg/kg, respectively. A matrix matching calibration strategy was employed to boost recovery results, and the acceptable recovery results were recorded between 95.9 % and 118.4 %. According to recovery results, the developed analytical method can be safely employed to determine the concentration of copper in rose tea samples accurately.

Impact of a cuff-based device calibration method on the agreement between invasive and noninvasive aortic and brachial pressure.

Brachial cuff-based methods are increasingly used to estimate aortic systolic blood pressure (aoSBP). However, there are several unresolved issues. to determine to what extent the scheme used to calibrate brachial records (1) can affect noninvasive obtained aoSBP levels, and consequently, the level of agreement with the aoSBP recorded invasively, and (2) how different ways of calibrating ultimately impact the relationship between aoSBP and cardiac properties. brachial and aortic blood pressure (BP) was simultaneously obtained by invasive (catheterisation) and noninvasive (brachial oscillometric-device) methods (89 subjects). aoSBP was noninvasive obtained using three calibration schemes: 'SD': diastolic and systolic brachial BP, 'C': diastolic and calculated brachial mean BP (bMBP), 'Osc': diastolic and oscillometry-derived bMBP. Agreement between invasive and noninvasive aoSBP, and associations between BP and echocardiographic-derived parameters were analysed. 'C' and 'SD' schemes generated aoSBP levels lower than those recorded invasively (mean errors: 6.9 and 10.1 mmHg); the opposite was found when considering 'Osc'(mean error: -11.4 mmHg). As individuals had higher invasive aoSBP, the three calibration schemes increasingly underestimated aoSBP levels; and viceversa. The 'range' of invasive aoSBP in which the calibration schemes reach the lowest error level (-5-5 mmHg) is different: 'C': 103-131 mmHg; 'Osc': 159-201 mmHg; 'SD':101-124 mmHg. The calibration methods allowed reaching levels of association between aoSBP and cardiac characteristics, somewhat lower, but very similar to those obtained when considering invasive aoSBP. There is no evidence of a clear superiority of one calibration method over another when considering the association between aoSBP and cardiac characteristics.