Liquid density measurement at low temperatures

AbstractHydrometers are widely used in industry for liquid density measurement. It is important to achieve rapid and high accuracy calibration for hydrometers. Based on the Archimedes principle, a fully automatic hydrometer calibration system in NIM was designed using Cuckow’s method. The liquid density of n-tridecane (C13H28)is calibrated with 441 g high-purity fused silica ring as the solid density standard. The buoyancy of hydrometer is measured by static weighing system with resolution 0.01 mg. The alignment between liquid surface and hydrometer scale was achieved by the lifting platform with the positioning accuracy of 10 μm. According to the weighing value of hydrometer in air and liquid, the density correction value at different scales is calculated. Hydrometer covering a full range (650–1500) kg/m3can be calibrated without changing the liquid. Taking the calibration data of PTB as reference, the experimental data show that the measurement uncertainty of this system is better than 0.3 division (k = 2).

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Investigation of the liquid density using Gamma scattering technique

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v1it1.438 ◽

2017 ◽

Vol 1 (T1) ◽

pp. 106-113

Author(s):

Kien Thach Trung Vo ◽

Tam Duc Hoang ◽

Nguyen Hoang Vo ◽

Chuong Dinh Huynh ◽

Thanh Thien Tran ◽

...

Keyword(s):

Multiple Scattering ◽

Density Measurement ◽

Single Scattering ◽

Photon Beam ◽

Scattered Photon ◽

Liquid Density ◽

Scattering Angle ◽

Testing Sample ◽

Scattering Technique

In this work, a gamma scattering technique using 137Cs (5mCi) source with the NaI(Tl) detector is arranged to record the scattered photon beam at scattering angle of 1200 for investigating the liquid density. We used standard liquid such as water, H2SO4, HCl, glycerol, HNO3, ethanol and A92 petrol to fit the single scattering peak, multiple scattering, and total counts versus standard liquid densities. The interpolating of the single scattering peak, multiple scattering, and total counts of the testing sample at scattering angle of 1200 is 0.702 g.cm-3, 0.783 g.cm-3, and 0.747 g.cm-3, respectively. The discrepancy of the experiment and true testing density is about 8 %, 3 %, and 2 %, respectively. The result shows that multiple scattering or total counts can be used to propose the density measurement.

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A new liquid density measurement method based on elastic spring stretching

Physics Education ◽

10.1088/1361-6552/abebb9 ◽

2021 ◽

Vol 56 (3) ◽

pp. 035026

Author(s):

Milan S Kovačević ◽

Marko M Milošević ◽

Željko M Cimbaljević

Keyword(s):

Measurement Method ◽

Density Measurement ◽

Liquid Density ◽

Elastic Spring

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Design of a Sensor System Using Fiber Bragg Grating for Liquid Level and Liquid Density Measurement

Sensor Letters ◽

10.1166/sl.2020.4304 ◽

2020 ◽

Vol 18 (12) ◽

pp. 889-893

Author(s):

Kalyan Biswas

Keyword(s):

Fiber Bragg Grating ◽

Density Measurement ◽

Sensor System ◽

Liquid Level ◽

Bragg Grating ◽

Liquid Density ◽

Bragg Wavelength ◽

Sensing System ◽

System A ◽

Level Monitoring

In this work, a simple but versatile sensing system for very accurate sensing of liquid level and liquid density is presented. The sensor works based on basic strain sensitivity of Fiber Bragg Grating (FBG) and principle of liquid obeying Archimedes’ law of buoyancy. In this system, a cylindrical shaped mass suspended from a Fiber Bragg Grating and partially immersed in the liquid to be sensed. If the liquid level in the container or liquid density varies, that change the up thrust on the suspended mass and load on the Fiber will be changed accordingly. The change in the load on Fiber changes strain on the FBG and the reflected Bragg wavelength also changes. The proposed device with proper calibration should be able to carry out real time and nonstop liquid level and liquid density measurements. A mathematical analysis of the system considering liquid properties and geometrical structure of the suspended mass is presented here. Sensitivity of the system for liquid level monitoring is also reported. Achieved results shows the path for the utilization of the proposed sensor system for precise liquid density measurement and liquid level sensing in very large storage tanks used for commercial/residential applications.

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