About Us

cavelamb himself[_2_]

DoN. Nichols wrote:

According to Eigenvector :

"DoN. Nichols" wrote in message
...

According to E Z Peaces :

DoN. Nichols wrote:

1055) Obviously a device for monitoring power line frequency. Power
line in part because of the lamp type screw base, and in part by
the frequency range covered -- about 45Hz to 85 Hz, so it would
work with both common power line frequencies -- 50 Hz and 60 Hz.

It is a vibrating reed, and you adust the free length by turning
the knob at the other end of the the cylinder which mounts the
reed, moving the pointer (and a clamp to effectively shorten the
reed, thus changing the resonant frequency.

You screw it in, adjust the two angle clamps to make it easy to
read and to access the knob, turn on the outlet, and adjust the
knob for the maximum swing (on the arc-shaped scale under the
reed pointer.

I don't see why a device to measure electrical frequency would be marked
in degrees if you rotate it or tip it.

I had agreed in another branch of this thread that it was not
for measuring electrical frequency -- but the mechanical frequencies
will be related to the electrical power frequency assuming an induction
motor instead of a series or parallel wound DC or universal motor.

You first tune it for maximum sensitivity to the frequency in
question, then you shift the angles and compare the maximum swing of the
reed. This lets you determine in which axis the vibration at that
frequency is at a maximum, and thus what is the likely component
contributing to the vibration, so you can work on balancing it.

Enjoy,
DoN.
--

That is an inertial balance. Its for the purpose of measuring the inertial
mass of an object.

http://www.physics.umd.edu/lecdem/se...osg1/g1-55.htm

That is a rather different device -- for demonstrating principles
in a physics lab. This device which we are discussing looks more like
something to use in the field.

The large brass screw near the bottom changes the pendulum arm length. The
weight at the top can be altered to increase the weight (hence the numbered
slots in the box).

What it's measuring - I don't know.

It is measuring the amount of vibration at a selected frequency
along a selected axis -- for the purpose of identifying the sources of
the vibration and eliminating or at least minimizing them, one at a
time. You select a frequency, determine along which axis it is
strongest, and work on balancing a device rotating at the proper RPM to
produce that frequency and oriented to produce the vibration along that
particular axis (that is -- perpedicular to the axis of rotation).

Not sure how much we will be able to follow this newsgroup for a
while, given that it appears to be under attack by massive cross-posting
to/from sci.crypt. I've set my killfile to eliminate those, but there
is bound to be a lot of discussion about that -- plus probably
cross-posting attacks from elsewhere as well.

Enjoy,
DoN.

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
What is it? CXCII	R.H.	Woodworking	45	August 16th 07 10:19 PM

Menu

About Us