01-01-2014 12:28 AM
Hi all.
I have used signal express for testing batteries under load.
Using temperature sensor, current sensor and voltage sensor.
I'm saving to TXT file, and imports to excel to make charge/discharge curves.
But have not found any way to measure delta temp (dT/dt)
I would like to measure temp every one minute and calculate the rise. If it goes over X deg. C per minute charging/discharging should stop.
04-30-2014 08:18 AM
Still struggling with delta/t or rise time.....
Is there anyone that can make a VI for me.
I have tried the "Acquire-and-Differentiate.seproj", it works and I get a accurate rise time (delta/t) if I simulate a "perfect" sawtooth signal. But I need to have longer time between samples (up to one minute) to avoid wrong readings (noise).
The readme for the VI says "Differentiation is not a native feature of Signal Express, but we are able to leverage LabVIEW features through Running LabVIEW VIs within a signal express project."
So I have given up to get this working in Signal express.....
06-30-2014 06:57 AM
Hi johannes_myhre,
I am assuming that you are referring to this reference example? Unfortunately, as you say, there is no way to do this natively in Signal Express. You need LabVIEW and the Mathematics API palette for full derivative functionallity.