DEIMOS Test #980401A
Shutter Impulse Test - April 1998
The DEIMOS shutter (for the CCD system) was tested for the
amount of displacement generated when the shutter operated.
A test was set up where the shutter (weighing 23 lbs.) was
clamped to a 340 lb. mass that was sitting on three small
blocks on the floor in the highbay. It was placed next to the
ESI test stand, and a Mahr gauge was attached to the ESI
stand with a mag-base holding the Mahr sensor to the end
of the shutter. The output from the Mahr meter was routed to
a storage oscilloscope and several plots of the excursions
the shutter made during operation were captured. The setup
was imaged, and a representative data plot has been scanned
and presented here.
First the shutter was operated on the Electronics shop bench
and it was determined that exhaust throttling was needed due
to the "slamming" at each end of travel. Plugs were then fitted
into the exhaust ports with a .070" hole to restrict air flow.
Since the solenoids require a minumum of ~40 PSI to latch and
operate properly, a pressure of 60 PSI was used for the test,
which should give reliable operation.
Scale for the test was found to be .0001"/.3 volt on the scope.
Several printouts of the shutter impulse were obtained.
An average p-p displacement of about .003" or ~75 microns was
found.
Click on an image to view larger version
