Hi Sceadwian,

I didn't take two lines of text to be a personal attack, but the two (too many) question marks preceeding the text.

No question that someone putting too many question marks in front of a sentence has no chance to survive in my company.

I guess we're here to help or get help. If the OP wants to measure the output of the sensor at a given temperature he must have a good reason for it.

Further I just repeated in short terms what everybody can read in the LM335 datasheet. I used it for a motorbyce handle heater circuit and you can bet the MCU has a software built in calibration routine. (works just comparing both sensor values (one known) and determining the offset).

No, I didn't have a nap today. We're going through the second f... hot season in Thailand (sun moves from North to South crossing Thailand at a 90deg zenith angle). Temperatures rise to 45deg/C at noon and that's not the time to take a nap.

Anyway, I feel fit and awake enough to read the poster's intentions.

Regards

Hans

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give me a break, your kidding I think.
maybe in the frozen arctic but the south pacific??

 

I was thinking of a concept of an anemometer. A reference temperature for the ambient and the external airflow temperature, and the difference between these two outputs should indicate airspeed, right?

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I apologise for offending you Boncuk, that was NOT my intention.

I often use the ??? prefix to mean "huh?" and what I meant was as much "huh? I don't understand?" as it is "huh? are you sure you are right?". My implication was that there seemed to be a difference between what you believed and what I believed. It was NOT a personal attack. If I attack you it will be most obvious.

Now back to the difference of OPINION, you stated the LM335 needs to be calibrated. See my post #12 and the quote I was referring to. I think your statement is wrong. I use LM335A quite often and they are usually within 1'C accuracy. I don't care if the datasheet says 3'C because in my real world experience all the units I have used have been within 1'C and my experience tells me that they DON'T need to be recalibrated for most general uses like temperature control and/or displaying 'C with a display where the PIC adc only gives 0.5'C display resolution.

If someone needs greater than 1'C accuracy that falls under the special needs category; ie "CAN be recalibrated for better accuracy", not the global; "NEEDs to be recalibrated" category.

 

Questionmarks seem to be your hobby.

It might not be realized by you that I'm German, just happening to live in Thailand. Germany gets pretty cold during the winter time and riding a motorbyce at -25deg/C is no fun even with heavy gloves.

Therefore I designed the handle heaters which almost instantaneously increase heating power if the driver removes one hand from the handle. Of course both handles are heated independently.

Any more breaks you need?

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You named it: LM335 and LM335A!

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heated handle bars
should market them--lol

 

They are.

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did you market them ??

 

Nope. I sold the design. I'm not interested in marketing anything in a country where I have no control what's going on.

I hate flying 12 hours to see what's happening.

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Thanks for the input. as for my intent. i am using two of the lm335s to compare temperatures between the two sensors. lets call them sensor a and sensor b. when a<b=pump off a>b=on the temp differentials should be within 1 degree. As one could deduce, the sensors are in a solar hotwater heater. a is the collector temp and b is the storage tank sensor.

 

The LM34 and LM35 are precalibrated and have accuracy of about 1 degree as I recall.

Attached Thumbnails

 

 

So does that mean it's feasible?

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-The kinda guy who would improvise so much that you'd say "Here's 50 bucks for your Gigantron"
http://vortexelectricaz.blogspot.com