Measurement Uncertainties of U-tube Manometers and Pressure Balances

Stuart, P. R.

doi:10.1088/0026-1394/30/6/036

Cited by 4 publications

(5 citation statements)

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“…Although this, too, has already been discussed by Bauer [2], an update is required as improvements have been made in the experimental methods and a more precise value is now available for the density of the mercury used in the manometer. This update is of interest for the interpretation of the data that the PTB contributed to the CCM barometer intercomparison [3]. The discussion of some experimental data illustrates the performance of the manometer.…”

Section: Introductionmentioning

confidence: 86%

“…The terms hg and h2 are mean densities calculated at the temperatures tHg and tN2 measured in the middle of the mercury line and the nitrogen line, respectively. The mercury density hg is calculated according to (4.2) of [4]: The nitrogen densities are calculated approximately from fi,(t, p ) = f i 2 ( f 0 , PO) l1 + ?&2 (tN2 -@/PO), (3) with 3kZ = (1/h2) (ahjar, = -1 p = -3,4i x 10-~ K-l (4) at T = 293,15 K. are discussed below together with their uncertainties.…”

Section: Calculation Of Measured Pressurementioning

confidence: 99%

“…The differences &t13 between the cistem temperatures and the mercury line temperature are typically of order 20 mK, although Figure 2 shows that less scatter of the temperatures is possible under favourable conditions. (The data in Figure 2 were obtained during one cycle of the measurements contributed by the PTB to the CCM barometric intercomparison [3]. Figure 3 shows the cor-responding effective area results in relative units.…”

Section: Uncertainty In Temperature Of Mercury and Nitrogenmentioning

confidence: 99%

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Use of a Precision Mercury Manometer with Capacitance Sensing of the Menisci

Jager¹

1994

Metrologia

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A commercially available dual-cistem mercury manometer, modified in some details, has been in use for many years as the main standard instrument of the PTB for the pressure range up to 200kPa (absolute and gauge). With this instrument the PTB participated in an international intercomparison of pressure standards in the barometric range, organized under the auspices of the Comitk Consultatif pour la Masse et les grandeurs apparentkes (CCM). An error analysis for absolute pressure measurements with the manometer is presented together with a discussion of experimental data and some technical details.

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Section: Introductionmentioning

confidence: 86%

Section: Calculation Of Measured Pressurementioning

confidence: 99%

Section: Uncertainty In Temperature Of Mercury and Nitrogenmentioning

confidence: 99%

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Use of a Precision Mercury Manometer with Capacitance Sensing of the Menisci

Jager¹

1994

Metrologia

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“…Note that an operating principle such as a manometer is also implemented by piston gauges (also known as pressure balances), albeit with a different mechanism of producing the pressure difference readout. The measurement uncertainty of U-tube manometers and pressure balances was investigated by Stuart [ 21 ]. Although manometers are not well suited for the measurement of highly aerated flows, certain flow problems can benefit from the measurement of the air phase.…”

Section: Methods For Measuring Free Water Surfacementioning

confidence: 99%

A Review on Methods for Measurement of Free Water Surface

Rak

Hočevar

Repinc

et al. 2023

Sensors

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Turbulent free-surface flows are encountered in several engineering applications and are typically characterized by the entrainment of air bubbles due to intense mixing and surface deformation. The resulting complex multiphase structure of the air–water interface presents a challenge in precise and reliable measurements of the free-water-surface topography. Conventional methods by manometers, wave probes, point gauges or electromagnetic/ultrasonic devices are proven and reliable, but also time-consuming, with limited accuracy and are mostly intrusive. Accurate spatial and temporal measurements of complex three-dimensional free-surface flows in natural and man-made hydraulic structures are only viable by high-resolution non-contact methods, namely, LIDAR-based laser scanning, photogrammetric reconstruction from cameras with overlapping field of view, or laser triangulation that combines laser ranging with high-speed imaging data. In the absence of seeding particles and optical calibration targets, sufficient flow aeration is essential for the operation of both laser- and photogrammetry-based methods, with local aeration properties significantly affecting the measurement uncertainty of laser-based methods.

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“…Preliminary results show that, above 40 kPa in the absolute mode, the mean value of effective area for almost all laboratories clusters in a band nominally 10 ppm wide [35]. A progress report by Stuart [36] on this study, which also includes gauge mode results from seven laboratories indicating "a significant difference between the results in the absolute and gauge modes", is included in these proceedings.…”

Section: More Recent Developmentsmentioning

confidence: 99%

A Review of Gas-operated Piston Gauges

Ehrlich

1994

Metrologia

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While hydraulic piston gauge technology dates from the mid-1800s, the first practical gas-lubricated pneumatic piston gauges for metrological applications were not developed until almost one hundred years later. The major reason for this delay was the need for adequate materials and machining technology to fabricate pistons and cylinders with tight enough tolerances for acceptable instrument operation. As the need for reduced uncertainties increased for gas pressure measurements in the ranges covered by manometry and above, technological improvement in gas-operated piston gauges advanced rapidly. Requirements for the development of high-quality air bearings added stimulus to the push for improved piston and cylinder technology. Investigations into the possible use of pneumatic piston gauges as primary pressure standards competitive with manometry had begun by 1965. Although lack of a fundamental detailed model of the vertical momentum transfer from the moving gas to the flanks of the piston currently somewhat limits this application, improvements in understanding and technology are continually being made. The relatively recent discoveries of the sometimes significant dependence of the effective area of certain pneumatic piston gauges on the gas species used during operation, or on whether the gauge is operating in the gauge or absolute mode, underscore the need for continued research in this field.

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Measurement Uncertainties of U-tube Manometers and Pressure Balances

Cited by 4 publications

References 1 publication

Use of a Precision Mercury Manometer with Capacitance Sensing of the Menisci

Use of a Precision Mercury Manometer with Capacitance Sensing of the Menisci

A Review on Methods for Measurement of Free Water Surface

A Review of Gas-operated Piston Gauges

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