05-20-2019 08:39 AM
hi, i'm using lm35 for temperature sensor and my data acquistion using NI MyRio 1900. i got problem , normal temperature is correct showing 25 but when given a hot temperature, the temperature should rise but the temperature actually drops below 25. Here is my program.
05-20-2019 09:26 AM
No, that's a picture of the Block Diagram of your LabVIEW Program. Attach the Program (hint -- it is a file with the extension .vi, unless you are using NXG).
Bob Schor
05-20-2019 09:39 AM - edited 05-20-2019 09:43 AM
How is the sensor supplied and connected to NI's interface ?
If you measure its output with a voltmeter, is it correct (250mV for 25°C) ?
How is the Express VI configured ? Why do you divide its output value by 2 ?
05-20-2019 10:12 AM
based on tutorial youtube, the sensor is supplied and connected to the NI interface as shown in the picture I inserted.
actually the output measurement is 500 mv for 50 °C, because I read the datasheet the normal temperature is 250 mv then I divide it by two.
05-20-2019 10:14 AM
here is my vi
05-21-2019 01:48 AM - edited 05-21-2019 01:58 AM
As you know (you wrote it in the documentation of your VI) the scale factor of the sensor is 10mV/°C.
Therefore you only need to multiply its output voltage in [V] by 100 (or to divide it by 0.01) to get the corresponding temperature in [°C].
500mV for 50°C --> 10mV/°C --> correct. At what temperature is the output voltage no longer right ?
05-21-2019 01:59 AM
The Express VI can't be opened without a NI MyRio.