Thermoworks TX-1001X-OP food probe


 

Peter F

TVWBB Fan
Again I am having difficulties getting enough ET73 probes from Maverick. At this point I am so frustrated by them that I'm looking for a different supplier for the 48 probes I need for the heatermeters that i'm building. One of the possible candidates is Thermoworks, the TX-1001X-OP probes are in a similar price range and compatible with the HM. Does anyone have good or bad experiences with Thermoworks or with these probes?
 
I have one and it works, however I have so many ET-72/73 probes I rarely use it so I can't say much more than that. You've just reminded me that I haven't done any noise measurement on it. I'll do that when I get home in a couple of hours and report back.
 
Again I am having difficulties getting enough ET73 probes from Maverick. At this point I am so frustrated by them that I'm looking for a different supplier for the 48 probes I need for the heatermeters that i'm building. One of the possible candidates is Thermoworks, the TX-1001X-OP probes are in a similar price range and compatible with the HM. Does anyone have good or bad experiences with Thermoworks or with these probes?

I've got 4 and love them.
 
The quality of the probes is very good. They have that nice thin tip that reacts quickly, and the guard on the where the wire goes into the probe helps keep moisture out which I think can shorten the life of any probe. Their connector is also the right size for standard jacks.

As long as nothing is touching the shield they're great however if you touch it:


ET-72/73 probes read 1 LSB peak-to-peak and this is about 16. 16 is the current cutoff in git that HeaterMeter will declare the data invalid, although I probably will up that a little. It stays pretty much centered on the right value (919). With the shield grounded they're perfect.
 
I have two of these probes, and they seem to work ok, but only if I ground the braided cable. If I don't ground the braided cable, then I get a no pit probe error whenever I touch the probe or braided cable. Sounds similar to this thread.. http://tvwbb.com/showthread.php?47598-HeaterMeter-working-however-only-when-holding-in-my-hand Has anyone figured this out? I've checked the grounding from the probe jack..

Anyways, the probes seem quite durable as we've used them with the Thermoworks ChefAlarm for quite a while. It is a bit annoying they need the shield grounded.
 
Yeah they're perfect with the shield grounded but if it isn't you'll get a graph like I posted. If you run the whole thing on batteries you shouldn't need to ground the shielding but you'd need a pretty big battery to run all day.
 
That's odd Rob, cause I have seen that behavior with all of my Maverick 732 probes, but haven't experienced that with any of the Thermoworks probes... Did you buy direct from Thermoworks?

Which version of the HM board are you running Rob?
 
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Yes, I bought them direct. I have a 4.1 board with the white wire fix.

Interesting though, I have two probes and they both respond the same. So, either its a bad batch of probes, or I did something wrong with the board? There is no continuity between the shielding and the ground of the board, or to the ground of the 1/8th inch connector.
 
I think maybe the difference is the HMv4.1 board, I am running a HMv4.0 board, the 4.1 board was a little more noisy than the 4.0. It is always frustrating when probes are flaky, when you plug them in you just want them to read solid and true.

It sounds like the braid may pick up some interference and pass that on to the thermistor when it touches something, or it somehow effects the thermistors potential to ground. I just tried to power up my multi-meter and the battery is dead so I can't test, is the braid completely isolated from the tip AND the shield of the probe jack?
 
I purchased mine directly from Thermoworks as well and as you can see it picks up a ton of noise. This would be a little higher on a v4.1 board. I show no conductivity at all between the braid and either part of the 2.5mm pin oddly enough.
 
So the braid is acting like an ungrounded shield I guess, which can pick up a lot of interference... Being isolated from the actual thermistor leads you would think that it would have no effect, I wouldn't expect the circuit to be so sensitive...

Rob, do these probes have the same behavior when plugged into the ThermoWorks base unit?
 
Yes, mine are the same. Less then an ohm between braid and probe, no continuity to the 1/8th inch connector. The ThermoWorks ChefAlarm works great, no problem.
 
The ThermoWorks ChefAlarm works great, no problem.
So there must be something about the impedance or sensitivity of the HM circuit that makes this happen. I assume the Maverick 732's work fine with the Maverick base as well. I wonder if we could come up with a schematic for either of these units and compare the probe circuits to what we have in the HM to get some hints at what might be different?
 
It's because they run on batteries. If you plug a 9V battery into the HeaterMeter barrel jack they have work great no matter what you touch the braid with.
 
It's because they run on batteries. If you plug a 9V battery into the HeaterMeter barrel jack they have work great no matter what you touch the braid with.

Oh, OK, that makes sense kinda, things always seem to run cleaner on a battery. Makes me wonder if the type of power supply has any effect on this sort of thing? I generally use an old school style transformer power supply, wonder if that provides better isolation than the modern switching mode power supplies? I guess I will have to experiment and see, I've got a bunch of 12V wall warts laying around...
 
It is possible that the type of power supply makes a difference. I've also tried isolating the probe grounds using ferrite beads and/or inductors without much luck. I even bought a different 12V supply (one that mentioned HeaterMeter on Amazon!) but there was no change. It still does it even when on my bench power supply.

EDIT: You can filter some of it out using an RC filter but there's just not enough room to fit 8 more components onto the HeaterMeter board.
 
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Try one of the old heavy wall wart power supply rather than the new lightweight switching mode models. I'm not SURE this will make a difference but I haven't had problems with my Thermoworks probes... 12VDC is a very common power supply, so I bet you have one around.... Cordless phone, old answering machine etc....
My Maverick 732's are totally unreliable without the braid grounded, so I use them as a second probe and use a clip to connect the braid to a Maverick 73 probe braid (which is grounded) and then they are fine...
Maverick 73 High Heat probes had been my favorite, cause they didn't have ground issue and they can stand over 700F, but they are not particularly resistant to water, I've soaked out and burned up a few of them for sure... I generally use a 73 as a pit probe and the 732 or Thermoworks as food probes, but am looking forward to moving to a thermocouple for the pit probe pretty soon here....
You could take a 2.5mm plug and wire an alligator clip to the ground and plug that into an unused probe jack then clip it onto the braid of the flaky probe... I know, not ideal, but it would work... Or alligator clip jumper wire from the probe braid the the rPi LAN housing, it sticks out enough to clip too...
I know Bryan has been working hard at eliminating noise on the probe lines so perhaps the next HM board release will be more forgiving of these grounding issues...
 
I will try a different wart tomorrow. I had thought of an alligator clip, but wondered how I would have 4 alligator clips for the probes. I wonder if I could solder something from the ground of the 1/8th plug to the braid? Anyways, thanks for the help.
 

 

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