Phidgets Forums

After using this set up successfully for months, suddenly I no longer get a connection with my K probe.

MacOS Big Sur
TMP1101_1 with TC on port 0
VINT HUB0001_0
Using it with Artisan

When I dbl-click on Thermocouple 0 in the control panel, I see “Temperature: ?” and an error event log pops up saying “Bad connection” repeatedly about every second.

If I dbl-click the channel 4 on-board temp sensor, it seems to work, showing a temp reading. So the usb and VINT hub seem to work ok.

I’ve reinstalled the latest control panel, tried the standalone panel, numerous system restarts, unplugging/replugging, checking all connections, etc.

I wish I had another probe or phidget I could swap in to see if it’s a hardware failure, but I don’t.

Please help. Has the phidget died? How can I test that? Should I see measurable voltage across the 2 leads to the probe when it’s connected? (I’m getting 0.)

Thanks.

The "Bad Connection" error occurs when the hardware detects that there is no reasonable connection between input and its associated ground. This typically means the thermocouple is screwed down incorrectly in the terminal block, or is broken.

Since you have double checked your connections, my best place to start would be trying a different channel, if you haven't done so already. Move the thermocouple over to channel 3, and see if the problem persists.

Rather than look at the voltage across when it is attached, I would disconnect the thermocuple and measure the resistance between the two wires. if the resistance is open/infinity, then the thermocuple is definitely broken. If you're getting a resistance measurement under 20 Ohms or so, it is likely ok.

Thank you for the quick reply!

Yes, I had tried a different channel with the same results.

Measures the resistance across the 2 wires and it is indeed open, so I guess it’s time to get a new thermocouple. Thanks for helping me solve that!

Now I’m curious, how fragile are these thermocouples generally? I can’t imagine how it went bad, but it does get handled every time I do a roast, putting it in and out of the roast chamber. I’ve been very careful with it though.

I think it depends on the thermocouple. Which one are you using?

This one:

uxcell K Type Thermocouple Temperature Sensor Probe 2x300mm (0 to 800C) 5ft Temperature Controller https://a.co/d/6WWoN6Q