Selection of Alternatives to Liquid-in-Glass Thermometers

Dean, SW; Ripple, Dean C.; Strouse, G. F.

doi:10.1520/jai13404

Cited by 3 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1. Published values for the SF6 TP from the literature as listed in GW [6]. Uncertainties for the data after 1990 are below 0.01 K and too small to be resolved on this scale.…”

Section: Thermophysical Properties Of Sf6mentioning

confidence: 99%

“…The values listed for Hg are from Mangum and Furukawa [11] and Furukawa [2]. For SF6, the TP temperature Ttp, pressure ptp, and liquid-phase density l, were taken from GW [6]. The solid-phase density s was extrapolated from literature values as discussed in Sec.…”

Section: Thermophysical Properties Of Sf6mentioning

confidence: 99%

“…Once widely used in science and industry, the MIG thermometer was already functionally obsolete as many practical and comparably accurate alternative thermometers have been available in the market for years. The market has already made adjustments for the MIG thermometer phase-outs, and standards specifying their use are likewise being revised or replaced [6].…”

Section: Introductionmentioning

confidence: 99%

“…In particular, the in-line gas purifier was not expected to remove the known N2 impurities, so we added a degassing step after the cell was filled by cooling the cell to approximately 100 K and pumping away any remaining volatile impurities. The pressure of SF6 at 100 K was calculated to be 2.7×10 −2 Pa based on the GW sublimation pressure equation [6]. The presence of volatile impurities (e.g., N2) would exert an additional partial pressure proportional to the concentration.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Realizations of the Triple Point of Sulfur Hexafluoride in Transportable and Refillable Cells

Tew

Quelhas

2018

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

The Minamata Convention on Mercury has created a near-term need to develop alternative fixed points to replace the mercury triple point (Hg TP) for calibration of standard platinum resistance thermometers (SPRTs) on the International Temperature Scale of 1990 (ITS-90). The sulfur hexafluoride (SF6) TP is a good candidate to provide adequate “drop-in compatible” replacements for the lowest costs. We report our first results of SF6 TP realizations performed at the National Institute of Standards and Technology (NIST) using a new series of transportable and refillable triple-point cells. The melting curves are presented at various melted fractions F and compared to evaluate the reproducibility and overall uncertainty for the realizations. We obtained a TP temperature of 223.55587(33) K at F = 50 % and 223.55607(35) K at F = 100 % as a weighted average of realizations using two adiabatic-type cells and two immersion-type cells. (Unless otherwise stated, uncertainties are standard uncertainties corresponding to a 68 % confidence level.) Temperatures were derived using a combination of five different SPRTs as calibrated at NIST on the ITS-90. The data were evaluated over a region of the melting plateau for melted fraction F between 30 % ≤ F ≤ 80 % with a 0.2 mK wide melting range. The results from the immersion-type cells were used to derive an experimental value for the SF6 TP static head correction of −11.6(1.7) mK/m. This value implies an initial slope of the pressure-temperature (p-T) equilibrium melting line of 1.55 MPa/K, whichis in agreement with the value predicted via the Clapeyron equation. The uncertainties of these initial SF6 TP realizations are limitedby uncertainty in the realization of the ITS-90 (0.25 mK) and, to a lesser extent, static pressure head effects and chemical impurities.

show abstract

“…1. Published values for the SF6 TP from the literature as listed in GW [6]. Uncertainties for the data after 1990 are below 0.01 K and too small to be resolved on this scale.…”

Section: Thermophysical Properties Of Sf6mentioning

confidence: 99%

Section: Thermophysical Properties Of Sf6mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Realizations of the Triple Point of Sulfur Hexafluoride in Transportable and Refillable Cells

Tew

Quelhas

2018

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

show abstract

Manufacturing and realization of the low volume fixed-point of sulfur hexafluoride (SF6)

Pavlasek,

Risegari,

Sparasci

2024

AIP Conference Proceedings

View full text Add to dashboard Cite

Maintenance, validation, and recalibration of liquid-in-glass thermometers

Cross¹,

Miller²,

Ripple³

et al. 2009

View full text Add to dashboard Cite

Liquid-in-glass thermometers are pervasive throughout industry. These thermometers provide a convenient method for measuring temperature over a broad range of applications with reasonable stability and accuracy. However, like all thermometers, liquid-in-glass thermometers are subject to drift as a function of time and maximum temperature of use. This paper describes methods for the validation and recalibration of previously calibrated liquid-in-glass thermometers to maintain the metrological traceability established with the initial calibration. Procedures and examples are given for visually inspecting a thermometer, using an ice point for a single-point recalibration, and determining uncertainties for thermometers with a single-point recalibration. We discuss when a single-point recalibration is acceptable, and when a full recalibration is needed.

show abstract

Selection of Alternatives to Liquid-in-Glass Thermometers

Cited by 3 publications

References 5 publications

Realizations of the Triple Point of Sulfur Hexafluoride in Transportable and Refillable Cells

Realizations of the Triple Point of Sulfur Hexafluoride in Transportable and Refillable Cells

Manufacturing and realization of the low volume fixed-point of sulfur hexafluoride (SF6)

Maintenance, validation, and recalibration of liquid-in-glass thermometers

Contact Info

Product

Resources

About