09-17-2015 10:42 AM
Hi I'm new to labview programming.
I'd like to create a VI to calibrate a temperature sensor. With the resources what I have I'm able to measure voltage fluctuations from the sensor. I'd like to convert them to respective temperature reading. For this I want to create a VI with which I can create a curve representing temperature for corresponding voltage value. Any help in this regard will be greatly appreciated. Thank you
09-17-2015 11:06 AM - edited 09-17-2015 11:08 AM
This should help you out:
http://www.ni.com/getting-started/labview-basics/
To make a look up table you can create two 1D arrays, one for the input measurement, one for the corresponding calibrated measurement. Use a "search for nearest element" vi (attached) and get the index. Then use "index array" on the calibrated measurement to get the value.
09-17-2015 11:16 AM
There are many maths functions in LabVIEW that will allow you to perform different types of calibration.
Do you have an equation that converts from voltage to temperature? You will be able to implement that equation in LabVIEW or if you just have an array of voltage/temperature values, you can do a lookup from the array with an interpolation to make it more accurate.
09-17-2015 11:22 AM
I do not have a equation for the conversion. I'd like to conduct a series of sample collections to formulate the equation.
09-17-2015 11:31 AM - edited 09-17-2015 11:32 AM
Oh, you mean you want a VI to produce the calibration curve/values, rather than just apply the calibration to convert between voltage/temperature.
What hardware do you have? You'll need to be able to measure and change the temperature and measure the voltage to get your calibration data!
In any case, I suggest you take some of the LabVIEW tutorials (there are free ones linked to here: https://decibel.ni.com/content/docs/DOC-40451) or look at the examples - there are examples of using Data Acquisition (DAQ) devices to acquire voltage/temperature data and plot this on a graph or log it to a file.
09-17-2015 12:13 PM
I have NI BNC-2110 DAQ to read the voltage value from the sensor. I'm using a external thermometer to read the actual themperature of the fluid. Now if I can get the corresponding voltage values to the temperature over say 25 samples I can fit a curve which would serve as a guide to predict the unknown temperature. The link given had nothing in it. Anyways thank you for help. Please suggest me if you have any ideas
09-17-2015 01:34 PM
First you need to learn your hardware and what it can do.
The NI BNC 2110 is NOT a DAQ hardware, it is a interface block for a DAQ hardware, so what DAQ hardware do you have?
Next the link should be: https://decibel.ni.com/content/docs/DOC-40451
There are multiple examples on getting a meassurement from a DAQ in both LabVIEW and using the test panels in MAX.
Do a little search in google.
09-18-2015 03:24 AM
The link broke because it included the ')' as part of the link, remove the ')' and you will get to a page and at the bottom is a list of various tutorials on LabVIEW.