Putting temperature probe in tubing?

Here on the forum there is a post where someone shows how he inserted the temperature probe into the tubing using a T-fitting:

For me cooling your K40 laser is one of the most important modifications you

So I ordered a bunch of T-fittings on Taobao:

However, playing with them and the probe, I’m not sure if it makes sense. If I push the probe all the way in, it will obstruct the flow, plus only the tip will be surrounded by fresh water:

Can this even work? Isn’t it better to put the probe into the tank?

Unless the flow sensor does not trigger, I assume the temperature in the tubing should be very close to that in the tank.

I would (and have) just put the probe in the tank.


I use a T connector (actually a pushfit connector). I protrude the probe only just into the water path, which I feel gives adequate contact without unduly restricting the flow. The metal casing has, I believe, better thermal conductivity than the water.

I actually have two sensors, one before and one after. I feel that the one before is required to ensure I’m providing sufficiently cold water and the one after shows, from the relative temperature, whether there is adequate flow.

I do have a flow sensor too, since the temperatures would not reflect the electrode temperatures if flow stopped.

This is overkill, of course. But who’d want to oversimplify it ? :slight_smile: