Really Felling Stupid here on this one

[MaxxxRacer]

I got my water probe thermocouples here but I have no way of getting them to acutaly take temps of the water in the lines. I was hoping that i could glue them in to some T lines but that didnt work out as the probe is stainless steel and nothing wants to stick to it very well.

If you guys have some tips on this it would be greatly appreciated.

[567234ta]

use plumbers putty :)

[killernoodle]

You can make anything stick to anything else with enough epoxy. If its really smooth/polished, rough it up with some sandpaper first.

[MaxxxRacer]

thanks guys.

I was using GOOP before... it iddnt want to stick to the plastic or the metal.. ill have to go buy some plumbers putty and some more epoxy..

[pHaestus]

I am not sure what size your probes are but here's what I do:

I use pvc crosses to hold the lines for dP xmitter and for the temp probes. The liquid passes stright through to wb. To hold the temp probes I use compression fittings. I rig my temp probes up by putting a little piece of vinyl tubing that is the same ID as the OD of the probe. Then I tighten that down into the compression fitting using that tubing as a kind of washer. Works fine for me.

[bigben2k]

Yep, that seems to be the easiest way:
http://wbta.us/bigben2k/4%20way%20cross2.jpg

If you get the schedule 80 cross, the connections will be threaded.

[MaxxxRacer]

hmm.. put a pressure barb on one side and the compression fitting on the other. can you guys help me find this stuff at mcmaster. the size of my probes are .13inches OD

[Javascripterror]

I use a threaded brass "T" . The two horizontal threads are used for the water flow line and barbed to fit the tubing size. The barb that will fit into the vertical thread is prepared with the probe by cutting a small piece of plastic in a circular shape to fit the inlet ID of the barb. Drill a hole in the centre of the plastic circle the same OD as the probe. Pop the probe through the hole and pull it into position in the bottom of the barb. Fill with epoxy to seal the unit. Simple matter then to screw the probe into position in the vertical part of the "T".

[bigben2k]

Yeah, what he said... :D

I'll be using a PVC 4-way cross, schedule 80. The top and bottom of the cross will be barbed. The sides will be closed with a simple cap, into which I'll be drilling holes for the temp and pressure probes.

http://wbta.us/bigben2k/cross%20assembly.jpg

[pHaestus]

why drill holes? Use quick disconnect fittings for the tubing. Don't epoxy or cement anything in place; what happens when you need to recalibrate or move a sensor around?

[pHaestus]

http://phaestus.procooling.com/pvccross.jpg

Somewhat antiquated photo (now I use RTD). I don't like the size of my crosses (that's 3/4" with a 1/2" NPT bushing gooped into it) but that was all I could find local. I would personally suggest the 3/8" crosses if you are buying from McMaster anyway.

I have some plugs for the dP connectors (the small tubing) that I made with a glass rod stuck inside the vinyl tubing. So I can move the temp probes around if I don't need to take pressure measurements.

Also be aware that you have to take measurements of the system with just a straight piece of tubing connecting the barbs and then cut that tubing in half and mount your wb or rad. Always use a standard length of tubing and make sure that everything is flat and straight. You then subtract the tube only numbers and you have the dP vs flow curve for your part of interest. Spend the time making those measurements on just the tubing and you'll get good with the instruments. The way Ben has his setup drawn there will be a 180 degree bend in the tube, which is not good for doing this measurement because the bend affects the dP of the tube.

[MaxxxRacer]

Well what i did is is got 2 3/8" T's and 2 1/2" T's (both are schedule 80 with npt fittings). I kinda like this idea better. i got 1/2" fittings for all of it too. got the compression fittings for the temp probe and got tubing for the dp meter i have.

so if i understand you correctly pH, i should take the dp of al of my tubing, fittings, rad and whatever else i have. Then i can do what exactly with this exactly? kinda lost on this as i have a dp meter so i can just hook it up whenever i want to measure the pressure drop of a particular item.

[mwolfman]

Maybe bit of topic, have anyone seen a tempsensor with more than one desimal acurasy? (0,01°)
I want to use it for flow mesurements...

[bobo5195]

thermocouples have more than decimal accuracy, its the measuring hardware thats problematic.

Im not so sure about flows sensors (which is what you might be talking about). A standard liquid in glass manometer could of an accuracy of greater than that, but mechanical stuff is problematic as small changes are going to effect things.

Tubing and plumbing will create losses which will effect your measurements of dp for the block as it will measure dp for the entire system (including tubing and fittings.)

[mwolfman]

nope, I want to messure the flow from the outside the tubing... the problem with watercoolingsystems is that the thermal power is to low (my system "only" produces 98.7Watt)...

[bobo5195]

temprature outside the system is not that difficult. Use a metal insert between two pipes and insulate it. After a time the metal insert with a thermocouple will balance its temprature with the water. This might take a little time but is not going to leak (well tube connections might). The convergence time may kill you but it shouldnt be too long (got an equation here but its horrible) and well insultated conditions might be possible.

[mwolfman]

hmm I don’t think you got the question right, I’m already measuring the temperatures outside the system... the problem is that my resolution is to low for measuring the flow with any accuracy (7,68 l/min with an StD of 2,32 l/min is not an good value)…