Hey I love talking about my tri-meter. You've given me another excuse. Thanks.
This is the exact make and model I have.
It's kinda' pricey. But if anyone is wondering if it's any good, it lasts and lasts, performing perfectly grow after grow with minimal calibrating.
The temperature / dissolved solids probe. A very solid metal piece encased in thick plastic. Very sturdy, and you don't have to worry about it drying out like the delicate PH probe.
Just dip it free floating in your solution like so. I took my plastic end piece off.
And the all important PH probe. You're gonna have to figure out a way to suction cup this to the wall of your fluid container.
Is the tip glass? I'm not sure, but the body of the probe houses delicate filaments that read the conductivity of the water. The probe bulb at the end is delicate and can never be allowed to dry out. It's protected somewhat by plastic protrusions.
And it's all powered via this unassuming ac wall plug.