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Measurement Uncertainty in Ultrasonic Exposimetry
Published in Marvin C. Ziskin, Peter A. Lewin, Ultrasonic Exposimetry, 2020
and usually expressed in percent. This nondimensional quantity provides a convenient way to compare precisions of different measurement procedures. This is valuable when the procedures being compared measure different physical quantities, and especially so when the quantities have different physical units. For example, a multimeter can be characterized as having a CV of 6% in measuring current and a CV of 2% in measuring voltage. It is immediately obvious that the precision in measuring voltage is three times better than that for current. This would not be so obvious had the precisions been reported as ±0.004 V and ±0.0001 A.
Electromagnetic Emanations from Power Sources and Fixed Specialized Equipment
Published in William J. Rea, EMF Effects from Power Sources and Electrosmog, 2018
Dirty electricity can be measured using an oscilloscope of a multimeter set for peak-to-peak voltage or a microsurge meter that provides a digital readout (Graham/Stetzer units) and is easily used by nonprofessionals. G/S capacitive filters short out high frequencies and reduce transients on electrical wiring with an optimal filtering capacity between 4 and 100 kHz. (Microsurge meters and filters are available.)
Development of a nitinol-actuated surgical instrument for laparoscopic renal denervation: feasibility test in a swine survival model
Published in International Journal of Hyperthermia, 2020
Donghyun Yim, Jinhwan Baik, Sangyong Lee, Sunchoel Yang, Chang Wook Jeong, Sung-Min Park
In strain tests, three-wire, pre-wired, and quarter-bridge SGs (KFH-06-120-D16-11L1M2S, Omega Engineering, Stamford, CT, USA) were attached over the bending surface of nitinol using cyanoacrylate adhesive (Z70, HBM, Darmstadt, Germany). Following excitation from a DC power supply (PWS4305, Tektronix, Beaverton, OR, USA) at 5 V, which is below the module’s maximum excitation voltage of 10 V, output voltage was measured using a 6-1/2 digit precision multimeter (DMM-4040, Tektronix, Beaverton, OR, USA). To detect small strain in the order of a few milli-strain, many SG circuit configurations include a Wheatstone bridge. Therefore, a SG, a power supply, and a multimeter were connected to a Wheatstone bridge completion module (BCM-1, Omega Engineering, Stamford, CT, USA) using screw terminals (Figure 2(a–c)).
Characterisation of fused deposition modeling 3D printers for pharmaceutical and medical applications
Published in Pharmaceutical Development and Technology, 2018
Tim Feuerbach, Stefanie Kock, Markus Thommes
For the evaluation of the temperature, the readings from the individual thermocouples of the respective printer were used. Set printing temperatures of 220, 240 and 250 °C were applied. The indicated temperatures were additionally validated with an external PT1000 platinum resistance thermometer (M1020, Heraeus, Hanau, Germany). The resistance of the PT1000 was determined with a multimeter (Digital Multimeter 79 II, Fluke, Glottertal, Germany). The PT1000 was positioned at the heating block surface closest to the position of the individual printer thermocouple. The distance between the PT1000 at the heating block surface and the printer thermocouple inside of the heating block was taken into account, with the calculation of the heat conduction over that particular distance based on the heating block material.
Of platelets and aggregometers: personal reminiscences of Gus Born (1921–2018)
Published in Platelets, 2018
The event which triggered my interest was a lecture in which the speaker had discussed changes in ion fluxes in platelets during aggregation. It occurred to me afterwards that these could be reflected by some corresponding changes in electrical properties of the PRP and, if so, these might be detected equally as well in blood. Accordingly, and in the best traditions of the amateur ‘tinkerer’, I attached two bent paper clips to the leads of a multimeter, set the instrument to measure electrical resistance, adjusted the sensitivity range and immersed this makeshift electrode assembly into a cuvette of PRP. I then added some collagen to aggregate the platelets and saw, to my delight but also great surprise, a small deflection of the needle of the meter. In retrospect, it is astonishing that such a crude set-up could have measured anything of physiological significance (the deflection was < 5Ω) and in fact, my attempts to reproduce this initially promising result, proved frustrating.