IMHO these systems are not really worth the expense. Infact systems based on pH can be misleading as the solutions are buffered, this means they will tend to keep a constant pH right up to the moment they fail, irrespective of the amount of active chemical in the system. You need something which measures the actual amount of chemical in the system and so far as I know this has to be titrated off line. I think you would be better off initially setting up some off line titrations to get some idea of the make up/usage. Using this you can then set a reasonably relevant work order for top up and for setting the period for routine change. This makes an easily manageable system and although it could be argued that you would be changing material unnecessarily the actual incremental cost of this is slight compared to the cost of continual monitoring. After the initial period occasionally doing a titration as a check or if works loads change. The only continuous in line monitoring that I would suggest would be on conductivity of [exiting] final rinse water. You can also set an upper limit on this to shut down if something goes completely wrong up stream. Regards Mike Fenner Indium Corporation T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Pb-free: www.Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Tom Gervascio Sent: Thursday, November 20, 2003 12:22 PM To: [log in to unmask] Subject: [TN] Automatic monitoring systems for in line cleaners We are considering using an automatic system to monitor and control additions of a saponifier to our Electrovert H400+ wash. Any recommendations on systems that other's have used? Any trade-offs on closed loop monitoring systems using pH versus refractometer? I thought that if you use water soluble masks that the dissolved materials might influence the dissolved solids measured with refractometer. However it seems that drag out with normal operation approaches 7 gal/8 hour shift. with a prewash and wash capacity of 95 gallons this means that over 12 shifts that the wash should be turned over but I suspect that all the material may not be turned over due to dead spots in the construction of the wash (i.e. 2" level in wash below a U joint that connects the prewash to the wash section). That said is location of the sensors critical- i.e. place them in these areas where the wash may be stagnant or items may settle to the bottom of tanks and heaters. Thanks for the input ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: This email, its content and any files transmitted with it are intended solely for the addressee(s) and may be legally privileged and/or confidential. If you are not the intended recipient please delete and contact the sender by return and delete the material from any computer. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. Messages sent via this medium may be subject to delays, non-delivery and unauthorized alteration. This email has been prepared using information believed by the author to be reliable and accurate, but Indium Corporation makes no warranty as to accuracy or completeness. In particular, Indium Corporation does not accept responsibility for changes made to this email after it was sent. Any opinions or recommendations expressed herein are solely those of the author. They may be subject to change without notice. ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------