From: bernardcleyet@redshift.com
Subject: Re: [Phys-l] Electromagnetic flow meter ?
Date: 2008, December 15, 09:55:37 PST
To: phys-l@carnot.physics.buffalo.edu
If the flow is constant wouldn't the signal be DC? also the salt soln. is
of high resistivity cf'd. to a Cu wire, therefore, one should use a high
(input) Z DC micropotential meter? [The O'scope in DC mode most sensitive
scale.] One could "chop" the soln.
In your "mind's eye" replace the liquid w/ a Cu block and calculate the
expected potential and where on the block the PD is expected.
bc lazy.
p.s. alternate expt. still the soln. and AC the coil. Note it's a half
turn down xformer. Expect pico V. output? One m/s is rather slow. (A
slow had wave.)
On 2008, Dec 15, , at 09:19, CARABAJAL PEREZ, MARCIAL ROBERTO wrote:
Yes, the conductive sensors are in contact with water, there are in an
horizontal plane.B vector is in vertical plane.
The direction of the electromotive force is based on Fleming's right-hand
rule
-----Mensaje original-----
De: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] En nombre de Bob
Sciamanda
Enviado el: lunes, 15 de diciembre de 2008 12:54
Para: Forum for Physics Educators
Asunto: Re: [Phys-l] Electromagnetic flow meter ?
As a first, cheap shot, are your conductive sensors on the INSIDE of the
tube - in electrical contact with the fluid? Also, check the direction of
the B field.
Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
trebor@winbeam.com http://www.winbeam.com/~trebor/
----- Original Message -----
From: "CARABAJAL PEREZ, MARCIAL ROBERTO" <mcarabajalp@ypf.com>
To: <phys-l@carnot.physics.buffalo.edu>
Sent: Monday, December 15, 2008 7:46 AM
Subject: [Phys-l] Electromagnetic flow meter ?
Hello:
We are trying to develop a lab experience building an electromagnetic
liquid flow meter 'magmeter'. We know that the operation of a magnetic
flowmeter is based upon Faraday's Law, which states that the voltage
induced across any conductor as it moves at right angles through a
magnetic field is proportional to the velocity of that conductor.
The liquid is salted water flowing at 1 m/s speed.
As a tube, there is an hypodermic syringe (1.25 cm diameter), with two
conductive sensors in oposite sides.
The magnetic field is provided by a 300 turns coil reeled on a TV flyback
ferrite nucleus, with a trasversal area of 1.5 cm2.
The driving current is 2 A alternate current (50 Hertz).
In the ferrite nucleus, there is a 1.25 cm gap, wide enough to hold the
tube (hypodermic syringe) inside it.
We expected an induced voltage, suitable to be observed in an osciloscope,
but we can´t measure any useful signal.
Has somebody carried out a similar experience? . Any suggestion?