Level sensor for hydrodynamics experiments

Abstract

An electronic system for the conversion of a liquid level into voltage is shown. This allows the student to carry out basic hydrodynamic experiments where fast liquid level changes occur. The use of this system is illustrated with the classic draining tank experiment.

An automated gasometer for the teaching laboratory

“…An initial attempt at automation was carried out with reference to a recent article by Aguilar [1]. A capacitance cell, placed inside the gasometer (figure 1) was formed with one plate being the water in the measuring cylinder and trough, the other plate being the interior of the wire (copperidentified as being orange in figure 1) with the dielectric being the enamelled coating, coloured red, on the copper wire (supplied by Maplin, item number YN79).…”

“…electrode. An astable oscillator (figure 2 in [1]) was connected to this capacitance sensor and a square wave output signal was obtained. Despite one's best efforts, this sensor did not provide a reliable measurement method.…”

“…Although Aguilar [1] chose a strategy of converting the square wave sensor output to level by a series of circuits, so giving students an opportunity to develop their skills in electronic instrumentation, the present work adopts a software conversion procedure.…”

Approximation of Torricelli's law with Euler's method and an instrumented water tank with ultrasonic sensor

“…Se han reportado estudios referentes al estudio de este clásico problema con la finalidad de promover el uso de diversos elementos físicos accesibles para los estudiantes en sesiones de laboratorio, por ejemplo, utilizando contenedores plásticos[5][6][7]. En favor de automatizar los procesos de adquisición de datos, es decir, la medición del nivel del líquido durante el proceso de vaciado de un tanque a través de un orificio, se desarrolló un sensor de nivel con componentes electrónicos[8]. Recientemente se utilizó un sensor de presión diferencial[9], mostrando las bondades de digitalizar el experimento utilizando dispositivos electrónicos.…”

An exact solution to the draining reservoir problem of the incompressible and non-viscous liquid

“…This allowed confirmation of Poiseuille's law (the relationship between the flow rate and pressure difference between the ends of the tube) for viscous liquids. In addition, Aguilar [4] used a level sensor to measure the water level in a draining reservoir.…”