large aperture shutters

[Klaus Reif]

Hi Bob and others,

we use a Melles Griot iris type shutter (04 IES 005)
with our 2kx2k 15micron CCDs. Its aperture is 60mm.

We have measured its delay times - relative to the 
falling/rising edge of the  signal - and opening times
at temperatures between -13C and +26C.

                T = 26 C    T = 5 C      T = -13 C
delay   (open)   20.8ms      20.2ms       27.3ms
duration(open)   14.5ms      12.5ms       18.0ms
delay   (close)  52.0ms      55.0ms       62.4ms
duration(close)  31.3ms      27.3ms       27.2ms

Errors are of the order of 2ms.

The shutter behavior is almost independent of the 
ambient temperature.

At the centre the exposure times are longer by about 
40 to 45ms compared to exposure times at a radial 
distance of about 30mm.

Due to different delay times exposures are about 30ms
longer than given by the control signal.

It would be very interesting to see how these values
compare to those of other large aperture shutters 
currently in use.


Klaus Reif

 ____________________________________________________________
|   Klaus Reif                                               |
|                                                            |
|   Radioastronomisches Institut                             |
|   der Universitaet Bonn                                    |
|                                                            |
|   Auf dem Huegel 71          reif at astro.uni-bonn.de        |
|   53121 Bonn                 phone: 49 228 737834          |
|   Germany                    FAX:   49 228 733672          |
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