2mV opamp

No it does not. Look up what a thermocouple actually is.

nope

As sphero pointed out Thermocouples are very unusual in consumer goods.

Used a lot in industry though e.g, for process temperature controllers.

I had a domestic boiler that used one but that was operating a valve directly, no electronics! :) I thought of scales but the ones I have seen all had an electronics tare function so was not sure if low offset was needed for domestic use.

I posted a reference to my latest, full bore turnkey design, but then YOU came back with a lame. Remember what I said... MY design, floor to ceiling. You deliberately failed to notice.

I guess you have a hard time remembering your denigrations. And that is why you get them back in your face.

So, 'lately' would mean in and during the last two years. But it was done a little less than a year ago, so nothing on a 'recent' burner.

The oven still works though.

Yeah, imagine a CPU chip that has an integrated thermocouple! Boggles the mind, it does.

Possibly in kitchen ovens that have electronic controls?

Oh... no. You are right... I missed the reference. Not a true bi- metallic thermocouple transducer.

More likely a thermistor type though, than a diode.

Yeah... I missed that, so you're right, of course. They are not cheap, and all require individual calibration to be useful. Not something one would find taking place on a production floor for mass produced consumer items.

That was common on gas water heaters with pilot lights. The t/c made enough current to hold open the safety shutoff valve.

I once had an old gravity heater (household furnace without a fan) that had an enormous thermocouple that actually powered the thermostat-gas valve loop. The t/c was about the size of a film can, and the pilot light was correspondingly big.

I thought of scales but the ones I have

Some sort of auto-zero can make low-offset circuits unnecessary.

Cool. Show it to us.

I worked in IR thermometry. I used $900 thermocouple devices which we then sent to NIST for full range cal certs and reference data, which cost more then the device itself did.

A nice feel to that... getting stuff right from NIST, since they bought our IR blackbody calibration ovens for their IR labs, and still do. FLIR buys our stuff too.

K. Irani invented the resistor bolometer back in 1960 (not the original ide, the original in-use devices). He started his company. Other folks followed, Raytheon, Honeywell, Etc. Heat seeking missiles came shortly thereafter. Now, we have micro-bolometer arrays giving full imagery, and FLIR came along (not in that order).

But yes, I know what they are and used them in our lab.

And no, it was not a meter. It was a two terminal thermocouple probe in a fitted wooden box. Nearly a foot long 'probe' A precision transducer instrument.

I do know what they are. I just misread the post.

Yes, I think that kind is only suitable for pilot light appliances which have been pretty much superceded by electronic ignition.

Low drift usually goes along with low offset- of course if it's zero'd at the beginning the only concern is if it drifts during the measurement. Still, I think I did see a low offset op-amp in an early load cell bathroom scale (very early and cheaper digital scales just had a quadrature pickup on a mechanical rotating disk, so subject to the same friction issues as purely mechanical cheap scales).

They are still used in gas ovens, dryers, and hot water tanks. Not exactly consumer goods inasmuch as scrapping one to get the part would cost more than simply buying the part from the maker of the appliance, water tank, etc.

no 2mV op amp either. Oh No! We highjacked his thread! NOT!

They were in the ENIAC. You know... the chip the size of a building...

Nope. Even the analog ones.

Furnaces, dryers, ovens, water heaters... any GAS operated devices have had them since the late seventies, analog or otherwise.

In the oven, it is what turns the gas valve on and off to regulate the temperature setpoint, which the main valve is set to. Also used for pilot sense. The oven valve will not open at all, unless the pilot has taken a thermocouple sense value over a specified threshold.

Same for gas furnaces and gas wall mounted space heaters, and hot water tank pilot sensing. The main vavle will not open until and unless the pilot is lit and STAYS lit. Any loss of pilot (or its thermocouple sensor), causes the gas valve solenoid to close. Usually a 24 volt system.

I found several references... here is one.

Nope. Shouldn't even be telling you about it.

They ought to, but the last time I looked they were using some crummy silicon resistive thing.

Yup. Now-a-days, many chips use the delta-I gimmick to get accurate chip temperature... process independent. ...Jim Thompson

depends on what you are referring to.

Gas oven will ALWAYS have a thermocouple failsafe solenoid valve on the main chamber feed requiring a live pilot at all times to remain open. The valves energization method may differ, but the trigger will not. It is the only thing that can stand directly in the flame for years and remain reliable.

Range top "burners" have no safety mech incorporated.

My i7 3930k has at least 13 individual sensors in it.

Here is what intel does. The actual mechanism is likely a diode for each location.

Den tirsdag den 3. februar 2015 kl. 20.18.40 UTC+1 skrev Jim Thompson:

I think the first FPGA I used ~15 years ago had two pins connected to a diode on the die so you could measure temperature

-Lasse