Re: Advice on INNOVA coolant flow sensor.

From: Eric Van Buren (aa9080@wayne.edu)
Date: Fri Jan 29 1999 - 10:44:08 EST


>>To anyone who may have come up against this problem: On my Coulter
>>EPICS Elite  I have an INNOVA 305  Argon Ion laser, only  about 100
>>hours on it. The water flow to the power supply  via  a new filter is
>>about 3.5 gal/min (verified  by measuring flow rate by volumetry).  In and
>>out flow to and from the power supply is correctly hooked up,  I know it
>>can cause problems if it is hooked up in reverse. The filter is not clogged,
>>the  hose is not crimped.  Still the  remote control display   registers 0
>>flow,  consequently  the laser cannot be powered up. Did anyone out
>>there  encounter this problem?  While I am in touch  with Coulter,  maybe
>>someone  knows,   Is there a valve or a flow  activated switch that got
>>stuck? Thanks  for any advice. Peter Bercz, USEPA/NERL EERD
>>Cincinnati
>
>Greetings Peter,
>
>I had this problem on an INNOVA 90 unit on our old EPICS C, I tracked the
>problem down to the flow sensor in the power supply box, if I remember
>correctly (this is going back some years) the sensor consists of an
>impeller connected to a rotary transducer which is driven by the cooling
>water flow through the passbank array. Now, under some conditions
>(infrequent use/closed circuit cooling) the impeller, which rotates in a
>fairly close-tolerance housing becomes clogged, the solution is to remove
>the cover to the flow sensor and clean inside.
>
>Best wishes
>
>Arnold.
>

Peter,

Arnold does a wonderful job of explaining the reason and solution for your
problem. I have cleaned this sensor on our Innova 90's several times. Our
laser cooling water supply is very rusty and this rust interferes with the
signal generated by the flow sensor. So, even though the impeller is
rotating properly (i.e., sufficient water flow), the laser control unit
receives a low water flow signal. In my case it is important to clean the 3
metal ends of the impeller as well as the sensor that detects these ends.

Good luck,
Eric

/\/\/\_ Eric Van Buren, aa9080@wayne.edu
\ \ \   Karmanos Cancer Institute and Immunology & Microbiology
 \_^_/  Wayne State University, Detroit, Michigan, USA



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