PH/ORP/Salinity Probes

[ShipWreck2]

So I am setting up my new aquarium and I was able to get my hands on a Siemens 226XM PLC and HMI. Since I program PLC's for a living I want to use it to control my tank.

I have 8 Analog inputs (either 4-20ma or 0-10vDC) that I would like to use for 2x PH, 1x ORP, 1x salinity and 2x Temperature.

I would like to use Precision Marine probes as they are readily available and inexpensive (compared to some others). Now my only problem is finding out what these probes require for supply voltage and what type of signal they return, and what range.

Does anyone know this or have other probe suggestions that this is available for?

[Donw]

Originally posted by ShipWreck2
So I am setting up my new aquarium and I was able to get my hands on a Siemens 226XM PLC and HMI. Since I program PLC's for a living I want to use it to control my tank.

I have 8 Analog inputs (either 4-20ma or 0-10vDC) that I would like to use for 2x PH, 1x ORP, 1x salinity and 2x Temperature.

I would like to use Precision Marine probes as they are readily available and inexpensive (compared to some others). Now my only problem is finding out what these probes require for supply voltage and what type of signal they return, and what range.

Does anyone know this or have other probe suggestions that this is available for?

Very high impedance mv. You need a transmitter to get 4-20 or 0-10. Not cheap!

Don

[ShipWreck2]

Originally posted by Donw
Very high impedance mv. You need a transmitter to get 4-20 or 0-10. Not cheap!

Don

Thanks for the quick reply. Do you have any actual numbers or examples of a transmitter?

[Donw]

Originally posted by ShipWreck2
Thanks for the quick reply. Do you have any actual numbers or examples of a transmitter?

Take a look at www.omega.com . The hanna mini panel meter ph controller has a 4-20 out put and the ranco temp has a 1-10v output. Those two may save you a few bucks.
Also take a look at my automation remodel thread there were a few others mentioned there.

Don

[pista01]

Look on e-Bay for pH transmitters. I found this one for about $30 -> http://www.sensorex.com/products/ph_...nsmitters.html

[ShipWreck2]

Originally posted by pista01
Look on e-Bay for pH transmitters. I found this one for about $30 -> http://www.sensorex.com/products/ph_...nsmitters.html

That's exactly what I was looking for. I can't find any on ebay though. Did you find this recently on ebay and do you have the auction #?

[smcnally]

I am a Crestron programmer, and I've been looking at doing the same thing with my processor for the last year. I've come to the conlusion that it is, IMO, just easier to get something like an Aqua Controller with RS232 or LAN interface and poll/parse it for information. The problem with trying to make your own system, is you will always question it's accuracy.

[ShipWreck2]

Originally posted by smcnally
I am a Crestron programmer, and I've been looking at doing the same thing with my processor for the last year. I've come to the conlusion that it is, IMO, just easier to get something like an Aqua Controller with RS232 or LAN interface and poll/parse it for information. The problem with trying to make your own system, is you will always question it's accuracy.

I program mutimillion dollar drinking water systems for cities. When I am done with a project I have NO doubt in it's accuracy or it is not done.

BTW, whats a Creston Programmer?

[smcnally]

Originally posted by ShipWreck2
I program mutimillion dollar drinking water systems for cities. When I am done with a project I have NO doubt in it's accuracy or it is not done.

LOL, you have way more skills than me. When you figure it out, will you forward me the info?

Originally posted by ShipWreck2
BTW, whats a Creston Programmer?

I program Crestron control systems. They are used in commercial and residential applications. Here's a link to one of the more common processors I use.
http://crestron.com/products/show_pr...ial&model=PRO2

[FuzzyLogic]

For critical things like temp and pH I would rather use dedicated controls rather than a general purpose controllers(PLCs). Most industrial applications work this way. Look for a pH analyzer/controller. This is a bit more expensive, but it is very reliable, general purpose controllers can crash and possibly cause overdosing. PLCs are great for data logging and display.

pH analyzers are pretty expensive new (usually starting at around $400). But you can always find them on ebay cheap. I got a Rosemount pH analyzer for $80 this is a $1200 industrial pH/Temperature analyzer AND transmitter. It outputs 2 standard 4 - 20mA signals that represent pH and Temp and it also displays it on the analyzer itself. Also has internal relays that you can program to control stuff based on Temp and pH.

[FuzzyLogic]

Here are the specs for the one that got off eBay for $70.88


Rosemount Analytical Solu Comp II Model# 1055-01-10-22-32 Dual Input pH/ORP Analyzer with two-line 16-character back-lit display.
Panel Mount with 115/230VAC Power

SW Ver# 3.17

INPUT: single or dual pH/ORP sensor inputs.
OUTPUT: two 4-20 mA or 0-20 mA isolated outputs.
ALARMS: three programmable alarm relays.

Measurement Range [pH]: 0 to 14 pH
Measurement Range [ORP]: -1400 to +1400 mV

Manufacturer data/manual:
http://www.emersonprocess.com/raihom..._51-1055pH.pdf

[pista01]

Originally posted by ShipWreck2
That's exactly what I was looking for. I can't find any on ebay though. Did you find this recently on ebay and do you have the auction #?

I bought this one about 9 months ago. I've seen them a few times since. I now see more of the ones that FuzzyLogic mentioned. I may pick one up for ORP.