Detachable temperature probes

[brewbear]

Hoping for some advice on this: I’m looking to get a detachable temperature probe. Needs to be detachable for storage and movement reasons. Eventually I’ll use a PID and SSR to control HERMS system (when I can justify that next upgrade!), but for the moment it will be monitoring temperatures only, attached to mashtun and CFC exit. I intend to get a PID and temperature sensor now, and then SSR + heatsink at a later date, just using the PID for temp readings at the moment.

Questions:

1. RTD PT100 versus thermocouples (K type etc) - " does it make a difference?
2. Will I need to use a thermowell, with the sensor slipped in and out of the thermowell? (as the Grainfather does, for instance). Or permanently attached temp sensor with plug-in lead?
3. What’s the best way to make the sensor detachable - " DIN plugs at each end? I’ve seen this RTD PT100 is made to be detachable, but it’s £15 and about 3 times the price of a non-detachable (but perhaps amendable) one?
4. PIDs - Chinese vs Inkbird etc. Are the cheap Chinese ones as good?

Any help or guidance very gratefully received. :thumb:

 

[brewbear]

I might have found the answers to some of my questions here and here.

Conclusions:
Q1 and Q3: Use three-wire RTD PT100 with DIN/ XLR plugs, because thermocouples are problematic to extend.
Q2: Get a SS thermowell because the probes aren’t always SS/ liable to rust
Q4: Stick to UK PIDs and RTD PT100s

Things I haven't resolved:

• Is there an RTD PT100 that can be slotted in to thermowell (without screwing in to a thread)? I can't find one yet and wondered if anyone has a recommendation. That would mean I could just buy one probe and move between thermowells.
• Is this the best way to do things, or am I missing something?

Any sources/ recommendations - be great to hear.

 

[nick9one1]

I use 'PT100 probe'. They take a couple of weeks to arrive, but they're the best I've found so far. Fully sealed and good quality stainless steel.

These are similar, but have a detachable din style connector on the probe, so maybe better fit for your requirements.

The cheap ones that come free with the C100's are't waterproof. If you look at the second picure you can see the probe is friction fitted inside the threaded part. Water seeps through.

Remember to set your PID to a PT100 if you go down that route. they normally come configured for a K type, and will mis-read if not changed over.

 

[brewbear]

Thanks, nick9one1: that's useful to know. I think I'll probably get something like the second link (probe for mash tun) and a PID. Then if quality of probe is fine, maybe order another for the CFC.

Thanks for the links.