Recent studies of float and stall curves in controlled-clearance deadweight testers with a simple piston

Newhall, D. H.; Ogawa, I.; Zilberstein, V.

doi:10.1063/1.1135979

Cited by 12 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,3,4 The third term, which describes the effect of ␦P j , now has a coefficient which not only is a function of the geometry of the instrument, the materials of construction, and the slope of the stall curve, but also takes into account the semi-infinite loading of the pressure measuring cylinder. If the observed stall slope is equal to or greater than the slope predicted by the method of Newhall, Ogawa, and Zilberstein, 6 there will be essential agreement between the elasticity method and the more complicated NIST experimental method. When the data from the Harwood found that the importance of the relative transmissibility of fluids was sufficient to justify the development of the equipment described earlier in the article and illustrated in Fig.…”

Section: Discussionmentioning

confidence: 93%

Revised characterization of the controlled clearance piston gauge

Newhall¹,

Newhall²,

Malloy³

2003

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

A revised equation is presented for the effective piston area of controlled clearance deadweight testers from the theory of elasticity which accounts for the semi-infinite loading of the measured pressure cylinder. The concept of pressure transmissibility expressed in terms of transmission delay threshold pressure and the importance in the choice of operating fluids is discussed. Test results illustrating pressure transmissibility for 25 different fluids at pressure between 138 MPa ͑20 000 psi͒ and 1380 MPa ͑200 000 psi͒ are presented, together with proposed ranking of the fluids based on their relative pressure transmissibility. The linear nature of the stall curve with fluids of high transmissibility and the resulting linear nature of the adjustments to the effective area are shown. The linearity allows the use of considerable extrapolation for making reasonable estimates of effective area, where direct knowledge of the slope of the stall curve is not known. The robustness of the new equation is demonstrated by applying the equation to data from two mercury point experiments at Harwood ͑9 years apart͒, several National Institute of Standards and Technology ͑NIST͒ characterizations of controlled clearance gauges, some other experiments at Harwood, and the data from NIST's experiment using a controlled clearance piston gauge to isolate the transition pressure of bismuth from Bi I to Bi II. The conclusions reached indicate that with suitable operating fluids, there is a negligibly small difference between pressure values calculated from the method discussed here and that used by NIST based on experimental determination of the jacket pressure coefficient.

show abstract

Section: Discussionmentioning

confidence: 93%

Revised characterization of the controlled clearance piston gauge

Newhall¹,

Newhall²,

Malloy³

2003

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

show abstract

“…The measurement procedure is essentially the same for this kind of experiment [1][2][3]. The piston was allowed to float for half an hour before recording any observations and this required bringing the system into the state of thermal equilibrium.…”

Section: Methodsmentioning

confidence: 99%

“…In this model [1][2][3], the pressure at the reference level of the gauge under constant floating conditions is defined as…”

Section: Heydemann and Welch Modelmentioning

confidence: 99%

“…The head correction term is defined as p = (ρ f − ρ air ) × g NPL H , where H is the difference in height between the reference levels of the two dead weight testers and ρ f is the density of the PTF. All the parameters in equation (1) can easily be evaluated except p z and d; p z is obtained from the fall-rate (ds/dt or v) of the piston from the fluid flow equation where the slope (κ) is assumed to be constant [1][2][3]:…”

Section: Heydemann and Welch Modelmentioning

confidence: 99%

“…A piston gauge is a device consisting of a finely machined piston housed vertically in a finely matched cylinder. The matching or the clearance between the piston and the cylinder surface is important to its performance and operation, because under the influence of pressure, particularly above 100 MPa, both the piston and the cylinder become distorted along the engagement length, which will result in a change in clearance and thereby the effective area of the assembly [1][2][3][4][5]. Additionally, at high pressure the viscosity of pressuretransmitting fluids (PTFs) changes drastically.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The effect of pressure-transmitting fluids in the characterization of a controlled clearance piston gauge up to 1 GPa

et al. 2007

View full text Add to dashboard Cite

The present paper describes the effect of different pressure-transmitting fluids (PTFs) on the systematic characterization of an oil-operated controlled clearance piston gauge (nominal diameter of the piston, 2.5 mm) in the pressure range up to 1000 MPa (1 GPa). Pure PTFs and mixtures of different PTFs are studied and four of them will be discussed here: namely (a) pure normal hydraulic oil (J-13), (b) a mixture of J-13 and an aviation turbine fuel (ATF), (JATF), (c) a pure di-ethyl-hexyl-sebacate oil (BIS) and (d) a mixture of white gasoline (G), J-13 and sebacate (GJBIS).The characterization is the measurement of the fall-rate of the piston as a function of applied jacket pressure (pj) with various PTFs using the method of Heydemann and Welch (HW model) (Heydemann and Welch 1975 Experimental Thermodynamics vol II, ed B Leneindre and B Voder (London: Butterworths) p 147). The analysis of the results is the determination of the cube root of the piston fall-rate (v1/3) with pj at different loads or measured pressures (pm). The linear portion of this v1/3–pj curve is extrapolated towards the null value of fall-rate, and the stall jacket pressure (pz) at different pm is obtained. It is observed that reasonably good fall-rate data could be obtained for J-13, JATF and BIS up to maximum pressures of 500 MPa, 700 MPa and 650 MPa, respectively. For GJBIS, these fall-rate data can be obtained up to a maximum pressure of 1 GPa. From the values of pz at different pm and also the values of the jacket pressure coefficient (d) along with other characteristic parameters in the HW model (Newhall et al 1979 Rev. Sci. Instrum. 50 964–8, Bandyopadhyay and Olson 2006 Metrologia 43 573–82), we have determined the relative standard uncertainties in the effective area (u(Ae)/Ae) for GJBIS up to 1 GPa for pj = 0 (free deformation mode) and pj/pm = 0.3. It is interesting to note that for pj = 0, at a pm of 100 MPa, u(Ae)/Ae is 74 × 10−6, while at a pm of 1 GPa, u(Ae)/Ae is 248 × 10−6. However, for pj/pm = 0.3, at a pm of 100 MPa, u(Ae)/Ae is 67 × 10−6, while at a pm of 1 GPa, u(Ae)/Ae is 125 × 10−6. A comparative study of u(Ae)/Ae has been elaborated with the four PTFs investigated. We have shown that at a pm of 100 MPa, u(Ae)/Ae is 202 × 10−6, 114 × 10−6, 66 × 10−6 and 67 × 10−6, for J-13, JATF, BIS and GJBIS, respectively, while at a pm of 500 MPa, u(Ae)/Ae is seen to be 97 × 10−6, 57 × 10−6, 46 × 10−6 and 56 × 10−6 for J13, JATF, BIS and GJBIS, respectively. Our measurements show that GJBIS is a convenient PTF for working up to 1 GPa. Finally, the results of the characterization are compared with the NPLI pressure scale through calibration of a NPLI secondary standard which is traceable to the LNE (France) pressure scale though direct comparison and participation in a recently concluded bilateral comparison with NIST (USA).

show abstract

Miscellaneous Cryogenic Design Aids and New Developments

Pobell

1996

Matter and Methods at Low Temperatures

View full text Add to dashboard Cite

Recent studies of float and stall curves in controlled-clearance deadweight testers with a simple piston

Cited by 12 publications

References 2 publications

Revised characterization of the controlled clearance piston gauge

Revised characterization of the controlled clearance piston gauge

The effect of pressure-transmitting fluids in the characterization of a controlled clearance piston gauge up to 1 GPa

Miscellaneous Cryogenic Design Aids and New Developments

Contact Info

Product

Resources

About