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Flow Controllers
Mark E. Chuck Wiley and Pete J. came over to
visit DND today where we are using the Proteus flow controller
in our x-ray setup. We plan
on using this same flow controller for water flow on our
beamlines. We have been concerned lately about actually recording
the flow rate as a function of time in a log just to look for signs
of trouble in the cooling system. We, of course, want to do
this as efficiently as possible (balancing cost, man power etc....).
While we have been discussing the various ways of recording this
info (Mark and I agree that logging this info through
EPICS may not be the ideal solution for us. Monitoring EPS variables
does not require the expense and complexity of a realtime
data collection system), the least expensive to record the data
for those of us using the Koyo 405 Programmable Logic Controllers
is to use the FACTS Magnetic Hall Effect Input module. I discussed
our application with FACTS Tech Support and it seems that this module
is designed exactly for this application. At 1.3 gpm, we
measured the Proteus putting out a rather gross looking ~200 Hz
periodic wave that spans about +/- 0.5 V which falls well within
the +/- 10 mV to +/- 10 V DC to 2.5 kHz signal that can be measured
by this module. The Proteus also has the low level setpoint
on the controller which closes a contact if the flow falls below
a preset value. Consequently, we don't have to rely on the
value read by this module to detect flow for EPS purposes
if we don't want to.
I have ordered one of the FACTS modules and will test it on our system
when it arrives. Hopefully, I will get to this the week of Jan 15.
I'll try and build a display similar to what we have for our
Bending Magnet Mono Vacuum and throw it up on the Web. (By
the way, the Linux box that is monitoring the vacuum pressure
has been collecting data like the 'Everready Bunny' for 64
days since its last reboot. You can see this by getting
to the link from the DND home page. Time is kept 'True' to
within a fraction of a second of pheobus using xntpd)
Now the price. Assuming you already have the Koyo 405 system,
the module is $441x(0.85 academic discount) = $374.85, but
this module measures 8 inputs so the cost per input is $45.
By our count, we will need one module per Front Optical Enclosure.
Since Koyo offers this module, it is very possible that Allen-Bradley
may also offer a similar one. While you lose the nice display of the
Love controllers, it does reduce the cost.
The reason that I'm posting this is that we are wondering if
we should try and organize a bulk order with Proteus. We
get a 12.5% discount if we order 25 at a time. I'm not
sure where the next discount break point is. The flow
controllers themselves are $335 a piece in Stainless Steel
with the meter option. Between DND, BESSRC, and UNI-CAT, we
are good for about 30 of these units.
Folks have told me that the flow meters periodically die. So, if enough
of us standardize on this flow controller, we might be able
to convince APS to carry it in the stockroom. Isn't this the
flow meter that SRI-CAT is using?
- John
--
John Quintana Internet email: jpq@nwu.edu
DND-CAT Synchrotron Research Center Voice Phone: (708) 252-0223
APS/ANL Bldg. 432/A003 FAX Phone: (708) 252-0226
9700 South Cass Avenue WWW: http://tomato.dnd.aps.anl.gov/~jpq/
Argonne, Illinois 60439