Oil Manometer Research Articles

Progress in development of an interferometric oil manometer

At PTB, a new interferometric oil manometer for the measurement of pressures below 2 kPa, is in development. This paper describes how the main quantities, length and liquid density, are determined, both in-situ, the latter for the first time in a primary pressure standard. The key features of both methods are presented.

Laser Interference Oil Manometer of State Primary Standard of the Unit of Pressure Get 101–2011

The design, principle of operation, and budget of errors of a laser interference oil manometer developed at the Mendeleev All-Russia Research Institute of Metrology (VNIIM) and subsequently incorporated into the State Primary Standard of the unit of pressure GET 101–2011 are described. The results of studies of precision instruments for measurements of pressure with the use of the laser interference oil manometer are presented. Summaries of key comparisons and international cooperation in the field of liquid manometry are presented.

Лазерный интерференционный масляный манометр Государственного первичного эталона единицы давления ГЭТ 101–2011

Лазерный интерференционный масляный манометр Государственного первичного эталона единицы давления ГЭТ 101–2011

Measurements of the Compressibility of Working Liquid of a Laser Interferometric Oil Manometer with the Help of a Low-Pressure Interferometric Piezometer

We developed a low-pressure interferometric liquid piezometer aimed at the determination of correction to the density of the working liquid of a laser interferometric oil manometer used as a component of the GET 101–2011 State Primary Pressure Standard for the range of absolute pressure 0.1–7·105 Pa. The indicated correction is caused by the compressibility of the working liquid. The comparison of the obtained correction with changes in the density of the working liquid as a result of its deep degassing (measured at the Physical Technical Institute, Germany) shows that, under the working conditions of the laser interferometric oil manometer, these two effects compensate each other almost completely. This confirms the reliability of the results of pressure measurements within the range 0.1–103 Pa performed by using the GET 101–2011.

Measurement of working fluid of laser interferometric oil manometer compressibility by the use of interferometric low pressure piezometer

Measurement of working fluid of laser interferometric oil manometer compressibility by the use of interferometric low pressure piezometer

A novel technique towards deployment of hydrostatic pressure based level sensor in nuclear fuel reprocessing facility.

A novel approach towards deployment of a hydrostatic pressure based level monitoring device is presented for continuous monitoring of liquid level in a reservoir with high resolution and precision. Some of the major drawbacks such as spurious information of measured level due to change in ambient temperature, requirement of high resolution pressure sensor, and bubbling effect by passing air or any gaseous fluid into the liquid are overcome by using such a newly designed hydrostatic pressure based level monitoring device. The technique involves precise measurement of hydrostatic pressure exerted by the process liquid using a high sensitive pulsating-type differential pressure sensor (capacitive type differential pressure sensor using a specially designed oil manometer) and correlating it to the liquid level. In order to avoid strong influence of temperature on liquid level, a temperature compensation methodology is derived and used in the system. A wireless data acquisition feature has also been provided in the level monitoring device in order to work in a remote area such as a radioactive environment. At the outset, a prototype level measurement system for a 1 m tank is constructed and its test performance has been well studied. The precision, accuracy, resolution, uncertainty, sensitivity, and response time of the prototype level measurement system are found to be less than 1.1 mm in the entire range, 1%, 3 mm, <1%, 10 Hz/mm, and ∼4 s, respectively.

FLOW BEHAVIOUR ANALYSIS ALONG AN ENGINE AIR INTAKE PIPE

There is a concern with the flow behaviour inside the air intake pipe that affects the desirable pressure ratio for inflow into the cylinder of an internal combustion engine. Measurements of flow along the intake pipe are required to better understand the physics of the intake system. This paper focuses on investigating the dynamics of the pressure profile along the intake pipe. The methodology involves experimental work utilising a red oil manometer to measure the pressure. Results analysis is presented as graphs of gauge pressures against engine speeds. From experimental results, the pressure profiles along the intake pipe were similar at different engine speed settings and pipe lengths. It was observed that the values of gauge pressure were lowest at the pipe entrance and it continued to rise along the pipe until it reaches the intake valve. This is a preliminary study looking into the effect of pipe geometry on the pressure dynamics.

A new primary standard oil manometer for absolute pressure up to 10 kPa

The National Institute of Metrology has developed a new oil manometer that covers the absolute pressure range from 100 Pa up to 10 kPa. The manometer is based on the ultrasonic measurement of transit time in oil columns, and a novel dual U-tube system has been designed to measure the speed of sound in real time as the pressure changes. The working fluid, di-2-ethylhexyl sebacate, was chosen for its sufficiently low vapor pressure and low sound attenuation. Each tube has a coating of Teflon to resist wetting by the oil. To obtain a uniform and stable temperature environment, the dual U-tube system is located inside a guard vacuum chamber that is wrapped with foam and aluminium foil. A vertical temperature difference of less than 20 mK, a horizontal temperature difference of less than 5 mK and a temperature stability better than 10 mK were achieved. The overall standard (k = 1) uncertainty of the oil manometer is estimated to be approximately (0.015 + 1.63 × 10−5 p Pa−1) Pa for absolute pressure measurements.

Results of comparisons of a laser interferometric oil manometer at VNIIM with the national standards of Finland

Results of comparisons of a laser interferometric oil manometer developed at the Mendeleev Institute (VNIIM), which reproduces the unit of pressure over the range 1–1000 Pa, with the national standards at the Metrology and Accreditation Center of Finland (MIKES) are described. The comparisons confirm the metrological characteristics of the VNIIM manometer and show that the size of the pressure unit reproduced by it agrees with the Finnish national standard.

A laser interferometric oil manometer as the primary standard for absolute pressure in the range 1 – 1000 Pa

The paper describes the principle and research of a new laser interferometric oil manometer for measuring low absolute pressure, which is being developed at the D.I. Mendeleyev Institute for Metrology (VNIIM). Surface waves in oil are effectively suppressed with specially designed floats supporting the thin near-surface layer in manometer tubes. A new approach to the research of capillary uncertainty is proposed. It is based on interferometric measurements of the oil surface curvature in manometer tubes and allows a correct estimation of the capillary uncertainty. Today the total uncertainty of the measured pressure P is estimated to be (1.0 + 0.01p/Pa)·10−2 Pa.

Thermodynamic studies on Rb 2ThO 3(s)

The Gibbs energy of formation of Rb 2ThO 3(s) has been determined using manometric technique. The equilibrium CO 2(g) pressures over the three phase mixture: {Rb 2ThO 3(s)+ Rb 2CO 3(s) + ThO 2(s)} have been measured using differential oil manometer in the temperature range 952–1098 K. The corresponding Gibbs energy expression as a function of temperature is given by: Δ f G m ° (Rb 2ThO 3,s, T) (kJ mol −1) ± 23 = −1691.4 + 0.280 T(K). The Δ f G m ° ( T) and Δ f H m ° (298.15 K) values have been estimated for alkali and alkaline earth metal thorates. An estimation method has also been developed for Δ f H m ° (AMO 3,s, 298.15 K), where A represents Li 2, Na 2, K 2, Rb 2, Cs 2, Ca, Sr and Ba and M represents Am, Ce, Cf, Cm, Cr, Ge, Ir, Mo, Np, Pb, Ru, Se, Sn. Tb, Te, Th, C, Hf, N, Pr, Pt, Rh, Si, Ti and Zr.

レーザ干渉式油マノメータによるゲージ圧力測定

レーザ干渉式油マノメータによるゲージ圧力測定

Thermodynamics of Air: Reinterpreting the Method of Clement and Desormes

The well-known Clement-Desormes method for heat capacity ratio employs a large bottle of air, an oil manometer, and a rubber pressurizing bulb. The air sample at slightly elevated pressure undergoe...

ヘテロダイン干渉法による油マノメータの液位差の精密測定

This paper describes the principle and performance of a novel interferometer developed for the measurement of differential height of an oil manometer for use in the range up to 1 kPa. The heterodyne interferometry using Zeeman stabilized He-Ne laser was applied to detect the displacement of oil surfaces which reflect laser beam directly. A system of double U-tube and double interferometer was introduced and developed in order to compensate errors caused by thermal and mechanical changes. The performance of the system was estimated from the experiments in which silicon oil of 100 mm2/s kinematic viscosity was selected as a manometer fluid. The short term and long term stabilities of zero-point are evaluated as standard deviations of 0.001 μm in 5 seconds and 0.01 μm in 3 days, respectively. The hysteresis of zero-point is 0.01 μm after 1 000 Pa pressurizing, during which the oil surfaces can be moved with a speed of up to 25 mm/min. The overall uncertainty of this system is estimated to be 0.026 μm.

An Improved oil Manometer

An Improved oil Manometer

2469. A sensitive oil manometer

2469. A sensitive oil manometer

A sensitive oil manometer

A simple, sensitive and accurate oil manometer for measuring pressures in the range 10-10-2 Torr is described. The principle of deaeration of oil in vacuum is used for removing soluble vapour and gases from the oil. The readings on the manometer are compared with those of a McLeod gauge.

An oil manometer for liquid helium vapour pressure measurement

A simply constructed oil manometer is described which can be used to measure the vapour pressure of liquid helium between temperatures of 4·2 and about 1·5 K. In this manometer the space above the liquid level in the closed arm is occupied by gas not vacuum.

Rapidly Degassed Oil Manometer

Rapidly Degassed Oil Manometer

Oil Manometer Safety Trap

Oil Manometer Safety Trap