I want a prog to measure temp with sensor lm35 with 9201 card

[ajju]

Hello Friends,

I am new in labview . i want to make a prog to measure temperature .i am having temp sensor lm35 . i m using this with 9201 card with cdaq 9172 chassis.please help me

[Coq_Rouge]

Asking question in this forum is much the same as asking your teacher for help. You have to compile some sort of list containing what you have done so far, and why you have problems. But every person in this forum have been new to Labview some time. So do not be afraid to ask questions. By the way Labview is shipped with tons of examples. Take a look at them. In the Labview tool bar go help and then Find Examples. Also never start a Labview session without enabling  Show Context Help. Same toolbar or Ctrl+h

[ajju]

sir

i m using temp sensor Lm35cz. i m giving 5vdc and gnd . i m connecting o/p pin to 9201 voltage card pin ai0.i m using cdaq 9172.Temp sensor has sensitivity 10mv/c.

i dont know wheather there is any need of scaling and calibration. i m using slope 50 in scale.

i m using formula node in this i m using formula   vout*2. but i m not getting correct temp range. even there is large variation in reading.

[JK1]

You have said that temp sensor has sensitivity of 10mv/C.  So if the output is 100mV then temperavture is 10deg C.

Your scaling will be multiply by 100.

Also you can measure the voltages for various tempertures and prepare a look up table.   Then on its simple job.  Just for the acquired voltage consult the look up table for temperature value and take as output.  Interpolate for the values not in table.

[Coq_Rouge]

Your NI 9201 has a input range equal to +/- 10 volt and 12 bit. This will give you a resolution equal to 20/4096= 4.88 mV approximately  pr bit. Your sensor will give 10mV/c. In other words you have only 2 bits resolution pr degrees Celsius. This is very poor resolution. Since your noise level will not be better than 2 bit at the best. Ideally you should find out what temperature range you are interested in and apply an analog amplifier so that the voltage from the  amplifier is 10 volt at max temperature