NTC Probes STC 1000
NTC Probes STC 1000
Apologies in advance but as per my previous posts I am not very swavvy when it comes to d.i.y. electrics. I purchased an NTC from MrLard which I would like to wire into my already assembled STC unit. I notice that there are 3 clips connections on the wire. The STC unit has 2 ports for the a probe to be connected. What I wanted to check was if this can be wired and secondly how to do so. As I said above I am not really experienced at all with this sort of thing so apologies for what may be a stupid question.
I plan to connect the probe to my conical fermenter to control my brew fridge.
http://brewbuilder.co.uk/index.php?_a=p ... duct_id=98
I plan to connect the probe to my conical fermenter to control my brew fridge.
http://brewbuilder.co.uk/index.php?_a=p ... duct_id=98
Re: NTC Probes STC 1000
Are you sure you don't have a Pt100 there? I see there are options for either in the drop down list
Re: NTC Probes STC 1000
Yep, you have bought a PT100.
Sabro Single Hop NEIPA 25/02/20 CLICK ME to monitor progress with Brewfather & iSpindel
Re: NTC Probes STC 1000
Yup regardless of what you ordered that's not what you need. It (PT100) will work very nicely with a PID like the Sesko / Auber but you need a two wire NTC... Sorry! The NTC probe just measures the resistance across the bulb so you shouldn't shorten or extend the cable or add additional junctions / connectors as you will impact on the reading. The PT100 has the two wires across the sensor but an additional return line which bypasses the sensor- this gives a "reference" so the sensor resistance can be worked out despite any changes to the resistance due to cable length and / or connectors.
NTC Probes STC 1000
Mmmmm, not quite.BenB wrote:Yup regardless of what you ordered that's not what you need. It (PT100) will work very nicely with a PID like the Sesko / Auber but you need a two wire NTC... Sorry! The NTC probe just measures the resistance across the bulb so you shouldn't shorten or extend the cable or add additional junctions / connectors as you will impact on the reading. The PT100 has the two wires across the sensor but an additional return line which bypasses the sensor- this gives a "reference" so the sensor resistance can be worked out despite any changes to the resistance due to cable length and / or connectors.
They both work the same way, just have different materials and range. A PT being the widest.
Both can be extended and jointed, that's why instruments have differentials/calibration functions on them.
The 3rd wire on a PT is not a by pass, it's used to lower the resistance of the conductor on long runs. It's joined directly on the other side of the bulb with the other. So, on a long run say 200m across a factory floor you would use a 3 core cable.
BOTH have to be calibrated with an accurate known source such as a thermopen as they have calibration certs. I have had STC's that have been close to 2 degrees out.
Sabro Single Hop NEIPA 25/02/20 CLICK ME to monitor progress with Brewfather & iSpindel
Re: NTC Probes STC 1000
Thanks, I can assure you that I ordered an NTC as at least checked that much in terms of the STC 1000. I'll contact Brew Builder.
Appreciate the clarification.
Appreciate the clarification.
Re: NTC Probes STC 1000
Spoke with MrLard who advised that all probes come with 3 wires regardless. All that is required is one of the red wires is used when connecting to the STC1000
-
- Telling imaginary friend stories
- Posts: 5229
- Joined: Sun Oct 16, 2011 1:49 pm
- Location: Cowley, Oxford
Re: NTC Probes STC 1000
well well now we know.. i too thought perhaps it was a pt100 shipped/ordered in errRhodesy wrote:Spoke with MrLard who advised that all probes come with 3 wires regardless. All that is required is one of the red wires is used when connecting to the STC1000
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate

Re: NTC Probes STC 1000
I thought they worked exactly opposite in that the NTC = negative temperature coefficient and a PT100 is positive.LeeH wrote:They both work the same way, just have different materials and range.
Re: NTC Probes STC 1000
They both work on resistance as you know. That was my point.AnthonyUK wrote:I thought they worked exactly opposite in that the NTC = negative temperature coefficient and a PT100 is positive.LeeH wrote:They both work the same way, just have different materials and range.
Sabro Single Hop NEIPA 25/02/20 CLICK ME to monitor progress with Brewfather & iSpindel
Re: NTC Probes STC 1000
I didn't want people to assume they are interchangeableLeeH wrote:They both work on resistance as you know. That was my point.

Re: NTC Probes STC 1000
true. I was confusing my ntc with my k-type thermocouples. Feel free to ignoreLeeH wrote:Mmmmm, not quite.BenB wrote:Yup regardless of what you ordered that's not what you need. It (PT100) will work very nicely with a PID like the Sesko / Auber but you need a two wire NTC... Sorry! The NTC probe just measures the resistance across the bulb so you shouldn't shorten or extend the cable or add additional junctions / connectors as you will impact on the reading. The PT100 has the two wires across the sensor but an additional return line which bypasses the sensor- this gives a "reference" so the sensor resistance can be worked out despite any changes to the resistance due to cable length and / or connectors.
They both work the same way, just have different materials and range. A PT being the widest.
Both can be extended and jointed, that's why instruments have differentials/calibration functions on them.
The 3rd wire on a PT is not a by pass, it's used to lower the resistance of the conductor on long runs. It's joined directly on the other side of the bulb with the other. So, on a long run say 200m across a factory floor you would use a 3 core cable.
BOTH have to be calibrated with an accurate known source such as a thermopen as they have calibration certs. I have had STC's that have been close to 2 degrees out.

Re: NTC Probes STC 1000
Not quite. BenB is actually correct regarding the use of the third wire, but 'by pass' is perhaps not the best way to describe it... the third wire is a compensation leg, it is used on long runs so the the controller/indicator can account for any intermediate wiring or connections.LeeH wrote:The 3rd wire on a PT is not a by pass, it's used to lower the resistance of the conductor on long runs.
It works by effectively subtracting the resistance between two red wires (to one end of the PRT and back) from the resistance between white & red wires (to the PRT, going through the PRT and back), to calculate the actual resistance of the PRT element. That way, any intermediate wiring has negligible effect on the measurement.
All resistance thermometers like NTC, PT100, etc. can be 2 or 3 wire configuration.
Re: NTC Probes STC 1000
Every day is a school day!
Sabro Single Hop NEIPA 25/02/20 CLICK ME to monitor progress with Brewfather & iSpindel