[labnetwork] Paging system

[Hathaway, Malcolm]

Hi Iulian,

At Harvard CNS we have a PA system, which includes a small signal amp.  It is quite audible in all the bays (one speaker per bay).  We tried out "talk back" speakers, which allow you to converse with cleanroom occupants.  However, since these are not full-duplex (i.e. you can't both be talking at the same time) and they are voice/sound activated at the cleanroom-end, we had the problem of ambient cleanroom noise triggering the "talk back" end during incoming speech, breaking up the incoming speech and making it pretty much un-listenable.  So we opted for one-way speakers, and use the bay phones for two-way communication.  The problem was worst in the plasma equipment bay, with all the various pumps running, as one might expect.  In the quieter bays (metrology, etc) the talk-back units worked okay.

I don't have dB numbers.

We have not noticed a problem with cell-phone usage in our cleanroom, either electromagnetically or particle-wise.  Potential problems may be limited by the fact that only Verizon cellphones will work down there (we have a Verizon repeater on that level.)


Mac
Harvard CNS

________________________________________
From: labnetwork-bounces at mtl.mit.edu [labnetwork-bounces at mtl.mit.edu] on behalf of Iulian Codreanu [codreanu at udel.edu]
Sent: Friday, October 24, 2014 1:41 PM
To: Fab Network
Subject: [labnetwork] Paging system

Dear Colleagues,

I would like to not allow cell phone use in the Delaware cleanroom; I
recall a long thread on this forum with various opinions on this topic.
Since I would very much like for my customers to be in touch with the
outside world while in the cleanroom, I have been trying to develop a
paging system that would work with the VOIP phone system.

The many pieces of the puzzle are coming together but I am struggling
answering a basic question posed by the "speaker guy": how noisy will
your cleanroom be?  That's a tough one because I will not know for a
number of years until the cleanroom is filled with equipment.

I would like to get an idea of how noisy fully operational cleanrooms
are (both the bay and chase areas).  Would you please share your knowledge?

Thank you very much!

Iulian

--
iulian Codreanu, Ph.D.
Director of Operations, UD NanoFab
University of Delaware
Office: 163 ISE Lab
Mail to: 250N ISE Lab
Ship to: 165 ISE Lab
221 Academy Street
Newark, DE 19716
302-831-2784


_______________________________________________
labnetwork mailing list
labnetwork at mtl.mit.edu
https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork