Hello, i am trying to take the measure of a temperatura but i couldn´t do it.

[miltonamp]

can u tell me how can i make a continuas thermistor measured? i need to take a real time temperature on a motor.

thanks 

[johnsold]

Please be more specific.  What parts work and what parts do not?

What kind of data acquisition equipment are you using?

Do you get data but cannot interpret it?

Lynn 

[miltonamp]

i am using a thermistor with a comuted source with debitts 12 v (like the phone charger). i use the Daq system to aquire signal but when i try it the signal with apears on the display (graph or thermometre) the values always jump and are not correct. Sorry for the foult of information but i really need to do it and i don´t really know how to start:)

Thanks

[johnsold]

OK.  So the first problem you are having is that you cannot successfully acquire the signal which you expect.

1.  What is the input range of the data acquisition device?  Many common devices will not accept 12 volts.  What voltage do you get across the thermistor when you measure it with a voltmeter?

2.  Are the jumps random or periodic?  Do they vary in time or amplitude?

3.  What is the model or type of data acquisition device? 

Lynn 

Message Edited by johnsold on 08-05-2009 02:56 PM

[AnalogKid2DigitalMan]

Also- are you measuring the voltage across a resistor in series with the thermistor? Please attach a sketck of the circuit you have and how it is connected to your card.

Also- what type of motor? It could be a source of electrical noise when it is operating.

-AK2DM

[Ray.R]

I agree with the above comments.

We would need to know more about:

1. which DAQ card you are using

2. what type of signal conditioning (if any) is implemented

3. the interconnection  / circuit relation between the motor and the thermistor

4. are you providing proper excitation current (if thermistor)

To learn more about LabVIEW, I suggest you try looking at some of these tutorials.

[miltonamp]

Sorry for the time that i take to answer.

Well, the thermistor is separeted from the motor, they have no relation. I just need the motor because is what i want to measure.

The current that u talking i thing that is provided by the transformer ( a phone charger).

I use the LabView 7.1 and the Daq that i instal is the 8.0.1... is that what u want?  

The aquisition device is the Nationa Instruments Cb-68LP

Thanks 

[johnsold]

The CB-68 is just a connector.  We need to know what kind of board it is connected to inside the computer.

Lynn 

[AnalogKid2DigitalMan]

miltonamp-

Your last post did not assist us assist you. Please attach a sketch of how you have your components wired. Also the CB-68 is just a connector block, not a DAQ card.

Please try to answer the questions from other members too.

Thanks

-AK2DM

[miltonamp]

sorry, i am new guy on that:) i will send u a foto with the schematic. 

Where i have to  look for the Daq card? inside the computer?