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Design and calibration of aninexpensive digital anemometer
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8/7/2019 Design and calibration of aninexpensive digital anemometer
Design and calibration of aninexpensive digital anemometer
R Hernandez-Walls1, E Rojas-Mayoral2, L Baez-Castillo3 andB Rojas-Mayoral4
1 Facultad de Ciencias Marinas, UABC, Ensenada Baja California, Mexico2 Centro de Investigacion Cientıfica y Superior de Ensenada, Ensenada, Baja California,
Mexico3 Facultad de Ciencias, UABC, Ensenada, Baja California, Mexico4 Facultad de Ciencias Naturales y Exactas, Unison, Sonora, Mexico
AbstractAn inexpensive and easily implemented device to measure wind velocity isproposed. This prototype has the advantage of being able to measure both thespeed and the direction of the wind in two dimensions. The device utilizes acomputational interface commonly referred to as a mouse. The mouseproposed for this prototype contains an optical sensor which allows it tosituate itself in space. The prototype utilizes a pendulum with an attacheddrag body. The pendulum’s drag body interacts with the fluid in motion,
causing an angle with respect to the vertical. The mouse measures thedisplacement of a sphere attached to the pendulum and calculates the angle.The resulting angle determines the relationship between the drag force andthe wind speed, thereby allowing the mouse to calculate the velocity. AMATLAB script was written to process the data received from the mouse.After calibration, the program determines the relationship between the pixelsmeasured and the pendulum’s angle, and so obtains information about thewind. This system (device and software) eliminates human error in datacollection and storage, thereby considerably reducing the time and costassociated with measuring wind velocity.
S Supplementary data are available from stacks.iop.org/physed/43/593
Introduction
One problem in meteorology is that of obtaining
reliable data in an autonomous way. In general,
meteorological instruments are expensive and
difficult to maintain. This problem can be solved
with a personal computer system. Any computer
system will contain input and output devices, such
as a mouse and a monitor. It has been shown
that a computer mouse can be used as an input
device for information [1–5]. The use of the
computer mouse as an electronic interface is analternative that avoids the design and construction
of an interface card between the computer and
a sensor [4]. In this article, a prototype of an
anemometer is proposed that utilizes an optic
sensor. Even though this prototype is similar
to a one-dimensional current meter, it has the
advantage of being able to measure the wind’sspeed as well as its direction [4].
The main disadvantage of this prototype isthat the mouse must be kept dry.
Conclusions
The measurement range depends on the drag body
and the precision depends on the volume of the
sphere: the bigger the sphere, the greater the
precision.
It has been shown that an optical mouse can
be used as an inexpensive sensor of geophysical
variables: in this case, the velocity of the wind
(speed and direction).
Acknowledgments
The authors acknowledge Andrea Lievana-Mac
Tavish for her suggestions and comments. The
first author also acknowledges support from SNI,
UABC and from SEP-CONACYT (Mexico) under
grants UABC-325 and SEP-2004-C01-47285.
Received 14 May 2008, in final form 30 July 2008
doi:10.1088/0031-9120/43/6/005
References[1] Ochoa O R and Kolp N F 1997 The computer
mouse as a data acquisition interface:application to harmonic oscillators Am. J. Phys.
65 1115–8[2] Yang Z and Maeda R 2000 Automatic micro flow
rate measurement using a modified computermouse device 1st Annual Int. IEEE-EMBS
Special Conf. on Microtechnology in Medicine
and Biology (France) pp 288–91[3] Modesto-Ortiz M, Martınez Y and Gonzalez J I
2003 Observaciones De Nivel Del Mar Con
Instrumentos De Bajo Costo. Reuni´ on Anual De
Geofısica (Mexico: UGM) p 159[4] Hernandez-Walls R, Luna-Hernandez J R,
Rojas-Mayoral E and Navarro-Olache L F 2004Dispositivo electronico, de facil construccion,para medir la velocidad de un fluido Rev. Ing.
Hidr´ aulica M´ exico 19 121–8
[5] Ng T W 2003 The optical mouse as an inexpensivedevice SPIE Proc. ETuF4 (San Diego, CA)
(Bellingham, WA: SPIE Optical Engineering
Press) pp 1–3[6] Roberson J A 1980 Engineering Fluid Mechanics
(Boston, MA: Houghton Mifflin)
Rafael Hernandez-Walls received hisPhD in optics from CICESE, Ensenada,Mexico. He currently works as aprofessor and researcher at the School of Marine Sciences of the UniversidadAutonoma de Baja California (UABC)where he teaches physics andcomputation, focusing on thedevelopment of new technologies for usein marine sciences.
Evaristo Rojas-Mayoral is a studentcurrently working to obtain his Master’sdegree in physical oceanography fromCICESE, Ensenada, Mexico. In 2005, heearned his Bachelor’s degree inoceanography from the UniversidadAutonoma de Baja California. Since2001, he has worked on the design andimplementation of new methods andtechnologies for measuring differentproperties of geophysical fluids.
Leonardo Baez-Castillo is a studentworking to obtain his Bachelor’s degreein physics from the UniversidadAutonoma de Baja California, Ensenada,Mexico. During his academic career, hehas participated in the design andconstruction of instrumentation for bothphysics and oceanographic laboratories.He is currently in the process of completing his thesis in biophysics,carrying out his research in the laboratoryof Animal Reproduction andImmunology.
Braulio Rojas-Mayoral is a studentworking to obtain his Bachelor’s degreein physics from the Universidad deSonora, Hermosillo, Mexico. Hisprincipal interest is in numericalmodelling and the realization of appliedexperiments.