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IC for temperature measuring with precision of 0.2 degrees C

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tranki

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I need a schematics or info about IC or other system for measure temperatures with a precision of 0.2 degrees C
 

marcosax

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termistor kty10

You can use LM92 from national or Dallas/maxim DS18B20
+/-0.5C
 

ebenni

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ds18b20 outdoor accuracy

use one transistor and 12 bit adc but calibration is very hard.

<font size=-1>[ This Message was edited by: ebenni on 2002-02-25 02:51 ]</font>
 

M

mrlogical

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application cd4538

Try the Nat Semi LM35DZ. gives an output of 10mV per degree 'c'. Connect 10k resistor from output to ground will increase accuracy..
 

darksky041257

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cd4538 schematic

The dallas device works great and you can chain them.

It is possible to add calibrationcurve to get better than the published accuracy.
 

fingers

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c source temp sensor pdf

I'm not sure if this would help
but for circuit temperature monitoring you could use a ref02 which has a 2mV/Deg C temp coefficent.
 

C-Man

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how a plc measures temperature

At the company where I am working we use KTY10 resistors and a PIC16F877 to do this.

We developed a way that does not need any calibration ...

regards
 

kryoutloud

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kty10 source code

I can't believe that you don't use any kind of calibration!?
 

C-Man

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kty10-5

I meant you do not need to calibrate the circuit, all you need to do is set the temperature of the sensor once.

This will store an offset value in EEPROM and as long as you do not change the sensor everything will be OK.

regards
 

marie65

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i2c lm92

I used NTC thermistor, RTD, Dallas 1820, LM35, KTY10. The easiest to use was Dallas 1820. Anyway, ALL of them need calibration.
 

kryoutloud

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dallas ds18 visual basic example

To: Tranki
which temperature do you want to measure in which range.
What kind ouf output you like to get.
 

kryoutloud

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lm92 circuit

To: c-man
That's what people call calibration.

greetings
 

woody28

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theremistor

You Can use SMT160 Temp Sensor with pulse output you must measure pulse duration ,many source exist for doing that if you search on http://www.av.com.
 

dacadc

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shematic circuite smt160

I recommend radiometric or bridge platinum schematic + sigma-delta ADC (Analog Devices, Crystal). You have exellent stability + accuracy
 

StanleyB

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thermistor kty10

Tranki what range of temperature are you going to measure? Room temperature? Outdoor temperature? Hot water? Sub zero?

Some components and design perform differently or not at all if they use components that cannot cope with the temperature range you need the circuit for. Since you are looking for a very thight accuracy, you have to consider the rest of the circuit as well, not just the measuring sensor. Resistors change their value with temperature, as do capacitors. But this is not widely recognised by all designers.
Aare you also going to measure the temperature with a seperate probe, or do you want to use the component (i.e. LM35) as the probe? All these factors are important in your final design.
 

cyberatom

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ntc thermistor 0.1c

You could always use a thermistor plus resistor if you don't need high accuracy or else use an LM335
 

cyberatom

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interface adc0801 lm35

But the best way will probably to go with an LM92 which has a i2c interface
 

tranki

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kty10 application note

Well, I need measure air conditioned installations.

The range of temperatures is about -30ºC to +40ºC. The reason of precission is the problem. I find many information on IC's and schematic circuits for temperature measure, but I need a precision of 0.2ºC because the system uses diferential temperature between ambient and flow air conditioned temperature.

Thanks!
 

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