Inline Probe Holder

[Eel-byte]

Looking at building an inline probe holder. I've seen this one at Marine Depot, http://www.marinedepot.com/ps_ViewItem~idproduct~OP3175~idCartRow~14436652~isKit~0.html . I would like it to fit inline on 1/4" od tubing. I've seen a few homemade inlines, care to share your build? Thanks.

[coralfragger101]

I don't follow you.

What is it that you want the 1/4" tubing to fit on to?

1/4" OD tubing? That would be smaller than regular airline tubing. What is this for?

Probes are 1/2" which is why the holder that you see in the link is 3/4". It has to be a bit bigger than whatever it is holding.

[Eel-byte]

I guess I was a little vague, the probe would go inline to monitor the effluent leaving the calc reactor. I did find a few designs searching last night.

[therealfatman]

The standard probe is small enough to fit inside a piece of 3/4" threaded schedule 80 PVC pipe. It can be held in placed and sealed into the pipe with a Weldon #10 two part epoxy. Typically the pH you want to read is of the water within the reactor. If you do choose to use it in line just use a 3/4" schedule 80 threaded "T" fitting and use the appropriate reducers for the other legs of the "T" fitting. The actual bulb of the pH meter should protrude quite aways beyond the end of the pipe as it needs to protrude into the stream of water once the pipe is screwed into the "T" fitting. At least a 1" protrusion. I would assemble it with just the "T" fitting pipe and pH probe without the epoxy and check how far the probe must be inserted to make the probe bulb tip visible. The probe will build up a calcium deposit fairly quickly and will need to be cleaned with acid (or vinegar) so a ball valve between the reactor and the probe is a pretty good idea.

[coralfragger101]

I've read other threads that say they fit into the 1/2" JG fittings as well. No sealant needed.

[therealfatman]

<a href=showthread.php?s=&postid=14291884#post14291884 target=_blank>Originally posted</a> by coralfragger101
I've read other threads that say they fit into the 1/2" JG fittings as well. No sealant needed.

Most standard gel filled probes at 12 mm diameter (12 mm is 0.4724 inches) (Orion, Milwaukee and Pin Point are12 mm) will fit the John Guest fitting but you would need to drill out the inner lip on the fitting to allow the probe to penetrate far enough. The inner lip only allows the pipe or a probe to enter the fitting a small amount (roughly equal to the pipe's outter diameter or a little more. For a probe it needs to proytrude ll the wy through the fitting. Do not uses 1/2" JG 'T" fitting as it will quickly clog with calcium with the probe protruding into the water stream. Use a JG i/2"thraeded adapter screwed into a bushing that is screwed into a 3/4" "T" fitting.

[stugray]

I have also used a JG fitting from HD. I believe the fitting was meant for 3/8" tubing.

You pull out the tube retainer & gasket.

Run a 1/2" drill bit through the fitting & a probe slides right in.

I put the probe all the way in , spread on some silicone and pull back to the final location.

Works fine, but I have yet to try to remove an old probe.

Worst case, I buy a new JG fitting, but I am pretty sure I could remove the probe without damaging either piece.

I used mine to put a Ph probe in the lid of my CA reactor.

Stu

[coralfragger101]

<a href=showthread.php?s=&postid=14292521#post14292521 target=_blank>Originally posted</a> by stugray
(snip)

I used mine to put a Ph probe in the lid of my CA reactor.

Stu

That's what I need to do. Mine is just in an effluent cup at the present time. Althouth I'm not sure how much difference it makes actually being "in" the reactor or sitting in a collection cup of the effluent.

[das75]

ghetto, but into a cup as well.

If I want to check the system pH, just lift out and drop into the sump.

http://i67.photobucket.com/albums/h316/das75/holder.jpg

[Eel-byte]

Thanks guys for suggestions. I did find this schematic. Problem is finding all the plumbing pieces at my local hardware stores.

http://i572.photobucket.com/albums/ss163/eel-byte/probeholder.jpg

[das75]

Definitely looks more fancy than mine.

[stugray]

Eel-byte,

That looks WAY more compliacted then my suggestion above.

With just ONE of those ( 3/8" threaded JG fitting ), you are done.



das75,

One thing I DO like about the remote Ph Probe is you can: "If I want to check the system pH, just lift out and drop into the sump"

So now I have two probes.

Stu

[lobsterotomy]

You really only need these parts:
2 john guest fitting to 1/2" mipt (male thread) - effluent in and out
http://www.bwiplumbing.com/images/uploads/JGmaleconnector.jpg

1 1/2" Cord grip - find this in the electrical aisle of your local HD or Lowes
http://tennesseepump.com/store/store_psaccessories/files/pl_7_thumbnail_1.png

1 1/2" Tee fitting - fipt x fipt x fipt (female threads):
http://jjdownsplastics.com/prod_img/49/49.jpg
Screw in the JG fittings to either side, and the wire grip to the top of the tee. This will allow you to have the probe fully inside the pipe.

[das75]

other advantage of the cup is it's easy to take out, clean and place in the calibration solution to check if needs adjustment.

[lobsterotomy]

The probem with the cup method is the you are not measuring the true pH of the reaction chamber. The effluent degasses as soon as it's in a low CO2 atmosphere, so the pH you're measuring in the cup is higher than in the reactor.

But nonetheless the easiest, cheapest alternative.

[Eel-byte]

<a href=showthread.php?s=&postid=14294140#post14294140 target=_blank>Originally posted</a> by lobsterotomy
You really only need these parts:
2 john guest fitting to 1/2" mipt (male thread) - effluent in and out
http://www.bwiplumbing.com/images/uploads/JGmaleconnector.jpg

1 1/2" Cord grip - find this in the electrical aisle of your local HD or Lowes
http://tennesseepump.com/store/store_psaccessories/files/pl_7_thumbnail_1.png

1 1/2" Tee fitting - fipt x fipt x fipt (female threads):
http://jjdownsplastics.com/prod_img/49/49.jpg
Screw in the JG fittings to either side, and the wire grip to the top of the tee. This will allow you to have the probe fully inside the pipe.

That looks the easiest route for me :) Hopefully HD has everything I need.

[lobsterotomy]

They should have everything - the JG with the general plumbing, and the threaded Tee with irrigation supplies if not with general plumbing.

And don't forget the teflon tape! ;)

[therealfatman]

<a href=showthread.php?s=&postid=14294689#post14294689 target=_blank>Originally posted</a> by Eel-byte
That looks the easiest route for me :) Hopefully HD has everything I need.

I would use a 3/4" "T" fitting with bushings instead of a 1/2" "T" fitting as the smaller "T" fitting would likely clog fairly quickly around the the probe if the probes tip is inserted down into the water stream as it should be.

JG fittings are based on tubing out side diameter. A 3/8" fitting drilled out to 1/2" (13 mm) would be pretty drastic as 3/8" is 9.5249 mm. Enlarging the hole from 9.525 mm to 13 mm would likely remove the entire JG locking band. Using a 1/2" JG and drilling it out to 1/2" just removes the inner lip and not all or any of the locking bands inner diameter.

Of course drill bits in mm sizes are available at nearly all auto supply stores and possibly at HD or Lowes. With a 12 mm bit the probe would likely fit well enough in a 3/8" JG fitting without actually drilling out the whole locking ring and therefore no caulking or other sealers or glues would be needed.

[lobsterotomy]

Ah, I see. So if I'm building my reactor with 1/2" plumbing, should I use a 1" tee with reducer bushings where I connect the 1/2" pH probe holder to the rest of the reactor plumbing?

[Lost in Tanks]

This is the simplest IMO, and how mine is built (Eel-byte, that pic you posted is by Tom Wyatt a good friend of mine ;) and also where My Reef Creations got their design from)

http://www.myreefcreations.com/popup_image.php?pID=224&image=0

FWIW, you ahve to order the probe fitting in that pic, I used the JG fitting from HD or Lowes and drilled it out. It is available locally and seals without any silicone ;)

on the other hand I also have the cordgrip style holder like in the above pic, I prefer the JG fitting

[therealfatman]

<a href=showthread.php?s=&postid=14298202#post14298202 target=_blank>Originally posted</a> by lobsterotomy
Ah, I see. So if I'm building my reactor with 1/2" plumbing, should I use a 1" tee with reducer bushings where I connect the 1/2" pH probe holder to the rest of the reactor plumbing?
A 3/4" threaded "T" fitting as is usually used with threaded PVC pipe works real well. The "T" fitting will most likely be grey in color. The compression type fitting used for electrical extension cords etc works real well if theyare available where you shop. They are often a bit pricey but less than the cost of a drill bit and JG fitting. They require no caulking or epoxy and make removal of the probe easy for cleaning. Yes bushing will likely be needed to connect to the rest of your plumbing unless your store has a very wide variety of JG fittings. They do make the fittings that would work without bushings but most stores do not stock the 3/4" and 1" male threaded JG fittings.

The plastic electrical fitting would be available at any electrical supply house that normally supplies electricians and contractors if they are not available at your hardware store.

Ask for a nonmetallic cord grip.

[lobsterotomy]

Yep, the cord grip I found is all PVC/EPDM. I think for my reactor I will go with the 1" Tee, just because the other fittings are available to me.