adccommunitymod (AutomationDirect) asked a question.
PH monitoring
Created Date: March 26,2014
Created By: Bob S BN
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We would like to add PH monitoring to an existing water recycling system that has a newer AD PLC and HMI controlling all other aspects of the equipment. This is starting to look like a mess, what with recalibrations, probe replacements, etc. Anyone have any experience with a system out there that can give me a PH number to an analog input card on a PLC?
Created Date: March 26,2014
Created by: Cap
This is where I'm headed when I have to add PH to my WWTP system
http://www.hach.com/encapsulated-lcp-liquid-crystal-polymer-ph-sensor-4-20-ma-viton-2-wire-transmitter/product-details?id=7639990594&callback=qs
I 've had good luck with all the other sensors Hach makes..
Cap
Created Date: March 26,2014
Created by: Bob S BN
Thanks Cap. I looked at a couple others today on the order of this one.
How often do you need to replace that salt bridge, or the whole sensor?
Created Date: March 26,2014
Created by: Cap
I 've not used one.. this is what has been recommended by a local Waste Water guy..
I 've used other Hach Equipment in the WW System, and like it..
Cap
Created Date: March 30,2014
Created by: automa
I have used these : http://www.omega.com/pptst/PHTX014.html with good results. Haven't replaced one yet and they have been in service about three years. They stay pretty close. Annual calibration on requires a .2 adjustment or so. The process media is pretty clean though.
Created Date: March 31,2014
Created by: Bob S BN
Haven't replaced one yet and they have been in service about three years. They stay pretty close. Annual calibration on requires a .2 adjustment or so. The process media is pretty clean though.
That sounds more like it, thanks for the information.
Are you sensing in a pipe, or open tank?
If open tank, could you be so kind as to tell me which sensor is working this well for you?
EDIT, are you using one of the little black boxes, or the one with the display?
Created Date: March 31,2014
Created by: automa
It is in an open tank. I used the PHTX-11 Model.
Created Date: March 31,2014
Created by: Bob S BN
It is in an open tank. I used the PHTX-11 Model.
OK, that's the isolated transmitter with the built in display.
Do you know what PH electrode is attached to it?
Created Date: March 26,2014
Created by: Bob S BN
We would like to add PH monitoring to an existing water recycling system that has a newer AD PLC and HMI controlling all other aspects of the equipment.
This is starting to look like a mess, what with recalibrations, probe replacements, etc.
Anyone have any experience with a system out there that can give me a PH number to an analog input card on a PLC?
most have 4-20mA options from their controllers.
GfProbe/Amplifier have 4-20mA option (hidden) by connecting the 3 wire 5SL connections in loop with 24vDC (new models of amplifiers).
Hach & Walchem have 4-20mA option amplifiers