Induction probe determines levels of liquid metals

Mutual-inductance probe accurately measures liquid levels in a variety of liquid metals at elevated temperatures. It can be used in pyrochemical processes for the recovery of spent reactor fuel

A LabVIEW-based PI controller for controlling CE 105 coupled Tank System

In this paper, use of Proportional-Integral (PI) controller to monitor and control liquid level in an interconnected CE 105 model coupled tank is investigated. To achieve a system which can instantaneously and accurately control the liquid level in a coupled tank, two different PI controllers have been tested. The LabVIEW library for the PI controller is used to measure liquid levels in the coupled tank. The PI SubVI already exists in the LabVIEW library that gives reasonable performance but to get a better system performance and monitor the liquid levels more accurately another SubVI is derived from the PI controller mathematical equations. The practical results and the system performance of the second SubVI show a faster response and more accurate instantaneous data which minimises the error in the measurements to ±1 mm. Furthermore, the robustness of the controller to change in the system’s parameters is also investigated and established

Approach for improving measurement precision of multiphase liquid levels

The solution allowing to determine the structure and the layers parameters of the multiphase liquid in real-time mode is proposed. The method is based on using the periodic controllable loads in the measuring probe construction, which can change their own parameters at the required time moment. In the paper an algorithm for determination of the layers parameters of the multiphase liquid is shown

A simple opto-fluidic switch detecting liquid filling in polymer-based microfluidic systems

A novel detection scheme for detection of liquid levels and bubbles in microfluidic systems, using the principle of total internal reflection (TIR) is presented. A laser beam impinges on the side walls of a channel which are inclined at 45deg. In an unfilled channel of such a "V-groove", TIR deflects the beam by 90deg into a simple light detector. Upon the presence of liquid, the refractive index in the channel changes, thus eliminating deflection by TIR. The detection principle is robust, requiring no calibration, and tolerating alignment errors of the laser larger than the width and depth of the microfluidic channels. The machining of the V-groves can seamlessly be integrated into common polymer microfabrication schemes such as injection molding

Vapor ingestion in Centaur liquid-hydrogen tank

Vapor ingestion phenomena were investigated using scale models of the Centaur liquid hydrogen tank to determine the height of the free surface of the liquid when vapor is intially ingested into the tank outlet. Data are compared with an analysin and, is general the agreement is very good. Predictions are presented for minimum liquid levels required in the Centaur liquid hydrogen tank in order to prevent vapor ingestion when restarting the engines in space and the quantities of liquid remaining in the tank at vapor ingestion during main engine firing

Adaptive Dynamic Inverse Controller for Advanced Coupled Tank Liquid Levels System

Inversion technique has been successfully applied in the tracking control of many Multi Input Multi Output (MIMO) process of engineering as well as science. The difficulty in controller design on account of variations in process dynamics as well as interactions between process variables. In this paper, the combination of neural network and dynamic inversion control is applied in Coupled Tank System (CTS) tracking water level problem. The liquids need to be pumped in total process and stored in the two tanks which are coupled together for certain desired level. Transfer function matrix of the system is gained experimentally from the tension loop response of the system. The PID neural network (PID-NN) controller used as a desired system control. Within MATLAB environment, conduction of simulate experiment is to testify the operation of the system according to Settling Time, Rise Time, Steady State Error and Overshoot. Numerical simulations and experiments have both been conducted to prove the validity of the proposed method. It has been attested that capabilities of CTS are ameliorated by suggested proposed method

An inexpensive open-source ultrasonic sensing system for monitoring liquid levels

 Liquid levels are measured in a variety of agricultural applications, and are often measured manually, which can be time-consuming and labor-intensive.  Rapid advances in electronic technologies have made a variety of inexpensive sensing, monitoring, and control capabilities available.  A monitoring system was developed and evaluated for automatic measurement of liquid levels, and demonstrated by monitoring water levels in evaporation pans used in evaporation studies and irrigation scheduling.  The system is composed of an ultrasonic sensor, a microcontroller-based data logger, and a temperature sensor.  The ultrasonic sensor measures the distance from the sensor to the liquid surface.  Air temperature is measured by the temperature sensor, and is used to compensate for changes in the speed of sound due to air-temperature variations to improve accuracy of ultrasonic distance measurements.  The datalogger is programmed to take measurements and to store data on a memory card which can be downloaded for processing and analysis.  All components of the system were assembled in a PVC housing.  The system was tested in the field, and resulted in water levels measured by the system corresponding very closely to those measured manually (R2 > 0.98).  This system is inexpensive, with total cost of US$85, and easy to build, install, and maintain.  In addition to monitoring liquid levels, the system could be adapted to a variety of other measurements.   Keywords: Ultrasonic sensor, liquid level, microcontroller, open-source hardware, datalogger, USA

Implications of cavity, topographic and geologic influences on tilt and strain observations

Tilt and strain observations are importantly (pathologically at the 100%, typically at the few 10s% level) affected by cavities, topography, and geological inhomogenities; gravity observation are practically unaffected. The traditional earth tide observatory and abandoned mine or tunnel is a very poor place to measure body tides because of the complicated cavities, topography and geology. Instead, the ideal site for observing the body tide is in flat terrain with horizontally layered, mechanically homogeneous geology. Strain will be measured with long surface- or trench-mounted laser strain meters and tilt with long, surface- or trench mounted liquid levels, or with borehole tiltmeters. Horizontal geological discontinuities can produce large perturbations of the tilt and strain tides, and these perturbations, using the known homogeneous tidal strains and tilts, can be used in exploring local structure in favorable cases and, through possible time variations of tidal admittances, in predicting earthquakes

Liquid-level meter has no moving parts

An electro-optical system, without moving parts, reliably indicates liquid levels at cryogenic temperatures. Glass prisms, which act as liquid level probes inside the tank, extend from optically aligned photoelectric assemblies mounted on the outside