Hi, I am quite lost on how I should design an ADC or signal conditioning circuit to obtain a quantifiable value from the output of the sensors as shown in the attached figure. Should I use a Wheatstone bridge rectifier or would the ADC pin of an Arduino suffice?

Any help is greatly appreciated. Thank you in advance.

 

Welcome to AAC!
I'm surprised that silver paste is even usable as a temperature sensor? What is its resistivity and what sort of temperature coefficient does the resistivity have?
I suspect you will need a fair amount of amplification to get a suitable signal for input to an ADC.

 

The fact that the Kapton is flexible will be highly problematic,
as any flexing will probably change the Resistance much more than the surrounding-Temperature will.

You would probably be much-better-off using a standard-Thermocouple.
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Questions: What sort of resistance change have you measured with the anticipated temperature change?? The amount of change will determine what sort of signal conditioning is required to get a suitable signal for input to an ADC . In addition, since the "silver paste" sensor does not generate any voltage, a bias scheme will need to be provided.
We will also need to know the resistance at the temperature expected.
Once those values are defined then certainly an interface circuit can be designed.

 

What makes you think they are temperature sensors? They look like current shunts to me.

 

What makes you think they are temperature sensors? They look like current shunts to me.

Uh, the thread title perhaps?

 

Uh, the thread title perhaps?

The title says that it is a temperature sensor, it also says that the track is made of silver, and the photographs give approximate dimensions.
Only approximate dimensions are needed to work out the resistance as it is proportional to the ratio of length and width, which is 544:8. One assumption I will make is that the thickness is 35um, the same as a pcb track.
Resistivity of silver is 1.6x10^-8Ωm which means the resistance is 31mΩ for the larger one, half that for the smaller.
100Ω Pt100 sensors are tricky enough to use, requiring Kelvin connections and minimal operating current to avoid self-heating. How difficult would it be to use a sensor with 3000x less resistance?
So, either they are not silver, not the dimensions that the photos indicate, or not temperature sensors.

 

They look an awful lot like heaters. They may not be, but I’ve never seen a sensor like that and, well, heaters—lots of them.

 

The title says that it is a temperature sensor, it also says that the track is made of silver, and the photographs give approximate dimensions.

Your post follows one by @MisterBill2, so I assumed it was he you were asking. My post did not say I believe they are temperature sensors. It was merely a literal answer to why @MisterBill2 might think so. I also question that they really are temperature sensors. But, since I do not know what silver paste is, and I don’t know how much silver it might contain or what its resistivity might be, I cannot rule it out either.

 

Rather than idle speculation, we should allow the TS to provide data sheets for those devices. As well as answering the other questions.

Otherwise, it will become another of those famous AAC rabbit chases.

 

OK, GIVEN that the TS asked about "SENSORS" , I revisited the original post and see that temperature is only mentioned in the title.

I am not overly inclined to second guess folks, and so I provided the questions needed for developing an answer.

One guess could be that the temperature range includes the melting point of the plastic portion of the system. Another rational guess is that given no hint as to the exact composition of the apparently metallic material, it has a greater temperature coefficient than I am aware of. My experience has been that not everybody who shows up asking for a test system is already an expert on exactly what tests will be required. Thus I responded with questions.

 

And down the Rabbit-Hole we go ............

My guess is that the TS actually has no idea of what the devices are that he got for free,
and, for whatever his next project may be,
it probably needs some sort of a Temperature-Sensor,
or, the TS, in thinking that they might be Temperature-Sensors,
came up with a new project idea that they "look-like" they would be "perfect for".

I vote Heaters.
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MB2; my comment wasn’t directed at your reply.
Rather it is my exasperation at a very common occurrence, where a TS posts an ambiguous question, and having all of us, the AAC’s old farts, scrambling to comprehend the incomplete information.

 

Those might even be platinum RTD temperature sensors.
AND the question made sense to me, even though it did not include enough information to provide a useful answer.

 

Your last post only proves my point: you understood one thing, but I and others understood something else. Neither of us is at fault, but rather the TS was, because he NEVER provided any meaningful information nor replied to any questions.

This is already post #15 and I am sure that there will be more posts down the rabbit hole.

 

It also occurs to me that the TS may not use the same language as I do and that there may be a translation issue of some magnitude. Consider that little processor product where the sellers call everything by different names. "Silver Paste"might actually be describing vapor deposited nichrome used as a temperature sensor. Or some really exotic alloy that I am not familiar with that has a linear tempco over some specific temperature range.

 

I would use a small current probe around the silver trace

 

Until we get additional information most of us who are not familiar with the devices are just guessing. My guess is that the measurement scheme would be similar to what is used for the platinum RTD sensors.