The Gas Chromatographic Method in Measurements of Helium Concentration
The developed chromatographic system described her e, can be used for measurements of he-. lium concentrat ion in gr oundwater. The obtained level of helium detection for groundwater. samples of ...
Dynamic measurement of the helium concentration of
He concentration measurements were carried out using the Dynamics of ION Implantation and Sputtering Of Surfaces (DIONISOS) experiment [8]. Fig. 1 shows a top–down schematic of the measurement set up. Essentially, DIONISOS has the capabilities of ordinary Ion Beam Analysis (IBA) techniques with the added ability to …
Dynamic measurement of the helium concentration of …
@article{osti_1897986, title = {Dynamic measurement of the helium concentration of evolving tungsten nanostructures using Elastic Recoil Detection during plasma exposure}, author = {Woller, K. B. and Whyte, D. G. and Wright, G. M.}, abstractNote = {Helium (He) concentration depth profiles of evolving tungsten (W) …
Managing the Background Signal in Helium Leak …
shown, helium background in the testing area can greatly affect the ability of the leak detector to successfully find leaks this small. Any helium leak detector in sniffing mode can measure the ambient helium concentration in the test area and also help locate the source of helium contamination. Leak Background Leak Rate 5.00E-09 1.00E-07 1.00E ...
Helium concentration measurement in tungsten fuzz …
The concentration of helium in tungsten fuzz-like nanostructures has been measured by means of thermal desorption spectroscopy. Fuzz was formed on the W surface under intensive plasma irradiation at 1500 K. The helium content was measured first in the as-irradiated sample, and then in a similar sample with the fuzz mechanically …
Comparison of helium and hydrogen releases in 1 m3 and
As an illustration we are doing the simple following calculation: for a helium flow rate of 210 NL.min −1 a hydrogen flow rate of 218 NL.min −1 and the 4 mm injection diameter, the ratio of measured helium and hydrogen concentrations should induce a ratio of interface height of 1.09.
Helium concentration measurer, helium leak testing …
The HM100 concentration meter is the ultimate tool to ensure the quality of helium leak tests for all helium collector leak testing lines. Helium savings can be made by recovery but also by dilution, with a perfect control of the helium concentration. Alliance Concept manufactures helium concentration meter for leak testing applications.
SAPRE
CONCENTRATION METERS. To be used for helium concentrations measures from 1 to . Mainly for helium concentration measurement for the "Envelope method" tightness control. Thermal conductivity cell with no routine recalibratione; Built-in batteries supply, autonomy about 6H;
Helium concentration measurement in tungsten fuzz-like …
The concentration of helium in tungsten fuzz-like nanostructures has been measured by means of thermal desorption spectroscopy. Fuzz was formed on the W surface under intensive plasma irradiation at 1500 K. ... However, measurements of the He concentration in W fuzz using elastic recoil detection (ERD) method gave only He/ W = …
Dynamic measurement of the helium concentration of
Helium concentrations in W fuzz layers are measured at 1–4 at.%, which is lower than expected for the observed sub-surface voids to be filled with several GPa of helium pressure.
sir20215085.pdf
Table 1. Estimates by the U.S. Geological Survey in 2020 of national totals for recoverable helium resources from known natural gas reservoirs, by Bureau of Land Management-proposed helium-resource region. [P5, P50, and P95 are probability percentiles and represent the 5-, 50-, and 95-percent probabilities, respectively, that the true resource ...
Nitric oxide concentration measurements in low …
The temperature measurements confirm the expected flame temperatures of approximately 1800, 1630, 1560, and 1530 K for the four pressures, respectively. The decreasing temperature results from an increasing concentration of helium in the air mixture of 0.510, 0.600, 0.635, and 0.650 at 2, 4, 6, and 8 atm, respectively.
Schlieren measurements and analysis of concentration field …
This is accomplished by applying the quantitative rainbow schlieren deflectometry technique to optically measure the local helium mole percentage across the whole field. Data were acquired over downstream locations extending from tube exit to about 3.0d (d=31.8 or 19.1 mm is the jet tube inside diameter) at spatial resolution of 0.14 …
Standardisation of the measurement of lung volumes
The helium analyser should have a range of ∼0–10% helium, a resolution of ≤0.01% helium over the entire range, and a 95% response time of <15 s to a 2% step change in helium concentration in the breathing circuit. …
Ultrasonic techniques for detecting helium leaks
Outputs from the SAW thermal sensor are the resonant frequency shifts that depend on the temperature coefficient of LiNbO 3.In Fig. 2, we show the model predictions of the frequency shifts after the sensor is exposed to air/helium mixtures for 10 s versus helium concentration at three flow rates. Based on the model predictions, the SAW …
Measurement of Functional Residual Capacity During …
We measured the concentration of helium with a katharometer (Godart, response time 0.1 sec), at the expiration port of a Siemens-Elema-900 ventilator. ... An open-circuit helium method for measuring functional residual capacity and defective intrapulmonary gas mixing. J Clin Invest. 1954; 33: 1277-1286. View in Article Scopus (12) ...
The Helium Closed Circuit Method for Measuring the …
The simplified helium method for measuring the FRC is described and results obtained in normal and emphysematous subjects are presented. 2. Minute-to-minute changes in helium concentration during the rebreathing period may be plotted against time to represent qualitative changes in intrapulmonary gas mixing. These curves correlate well …
Increasing atmospheric helium due to fossil fuel exploitation
Measurements of the 4 He/N 2 ratio in 46 high-pressure samples of archived old air using a new mass spectrometric technique 25 reveal an atmospheric build-up of 4 He of 0.042 ± 0.003‰ yr −1 ...
Helium dilution technique
The dilution principle – measurement of fluid compartment volume; Diffusing capacity; Compliance; Bohr equation; Alveolar ventilation equation; Alveolar gas equation; Helium …
Measurement of functional residual capacity by helium
Objective Measurement of functional residual capacity (FRC) during controlled and especially during assisted ventilation remains a challenge in the physiological evaluation of ventilated patients. To validate a bag-in-box closed helium dilution technique allowing measurements both during pressure-controlled (PCV) and pressure-support …
Guide to Helium Leak Testing
There are 2 basic techniques; high vacuum testing which allows leak test thresholds to be set down as low as 1×10 -12 mbar.l.sec -1, or sniffing which is generally used for helium leaks down to 1×10 -6 mbar.l.sec -1. For reference 1 cubic millimetre per second is approximately 1×10 -3 mbar.l.sec -1. or 1cc is approximately 1mbar litre per ...
Measurements of metastable helium in Earth's …
These measurements provide crucial validation to space weather models, support predictions of peak number density ( ~ 1 cm −3) and the dependence of density …
Multiple breath helium dilution measurement of …
The helium analyser should have. range of about 0–10% helium, a resolution of 0.01% helium or better over the entire range and a 95% res-ponse time of less than 15 s to a …
Application of rainbow schlieren deflectometry for concentration
The rainbow schlieren deflectometry technique was used to measure oxygen concentrations in a laminar, isothermal helium jet discharged vertically into ambient air. The concentration distributions were inferred from the color schlieren image by taking into consideration the sampling interval and noise in measurements, especially near the jet …
Quantitative concentration measurements in a turbulent helium …
Abstract Rainbow schlieren deflectometry (RSD) is applied to acquire quantitative concentration measurements in a turbulent environment for the first time. RSD methodology is developed and validated using Rayleigh scattering data available in the literature. Experiments were performed in an initially laminar, momentum-driven …
Nitrogen washout/washin, helium dilution and …
End expiratory lung volume (EELV) measurement in the clinical setting is routinely performed using the helium dilution technique. A ventilator that implements a simplified version of the nitrogen …
Helium concentration in the earth's lower atmosphere
A helium content of 5.222 + or - 0.017 ppm by volume has been established by measurements during 1981 of the earth's lower atmosphere, using isotope dilution mass spectrometry. This compares well with the currently accepted value of 5.239 + or - 0.004 ppm determined by Gluekhauf (1946) on the basis of measurements conducted in the …
Helium
Amount of helium in the reservoir = concentration of helium (C 1) × volume of gas (V 1) •. After several breaths the helium equilibrates between the reservoir and the lung, leading to a new, reduced concentration of helium in the reservoir (C 2) •. The change in concentration allows a calculation of TLC (V 2) •. •.
HELIUM CONCENTRATION TESTER
HELIUM CONCENTRATION TESTER LHCT03D LACO's LHCT03D helium concentration tester is designed to measure helium concentration in production parts previously filled with helium gas. Working in conjunction with a helium mass spectrometer, the LHCT03D provides excellent accuracy and fast response time. Includes the LSP-HCT-5 sniffer …
Predictions and Measurements of Helium and Hydrogen in …
Combining earlier measurements of helium at lower dpa levels with knowledge of the 59 Ni behavior we can extrapolate to higher dpa levels since the helium concentration is an excellent retrospective dosimeter of the thermal fluence. Predictions of hydrogen are more difficult, however, due to helium-nucleated cavities storing both …