Define what "not stable" means. Compared to what? You mean the measured pressure value (voltage output of the sensor) is not stable? Quantify it! What is the standard deviation of the measured signal? Do you have a datasheet for these pressure transducers? What is the specified accuracy, noise level, temperature sensitivity? First you need to study your hardware, then you can make clear statement about your expected signal. Also, do you use electromagnetically shielded signal cables? Grounding is properly done?
I do not think increasing the sampling rate will help you with the noise. You can "increase the statistics", and take an average of the signal in this way, lets say you can smooth your signal curve. But do not forget there is a certain "error bar" always, so you need to be aware of smoothing.
About the code: it looks like you still did not learn an important part of LabVIEW which is timing. You should understand what software timing means, and what are the limits.
"Using “wait “ at 1 ms only gives med 1 kHz. " No wonder, if you take the reciprocal of 1 msec, you get 1 kHz 🙂 You cannot go faster with software timed loop than 1 kHz, and even worse, at this level you can have few msec or higher differences between iterations.
I repeat, if you see an unstable signal, you should quantify it and compare it with the datasheet (you could attach your signal and also the sensor's datasheet). Then you can try to find the reason and how to fix this problem. Just simply increasing sampling rate will not solve the source of the problem. And after all this, if you still need higher sampling rate (I doubt), you need to learn how to do hardware timing using DAQmx functions (my code simply does software timing, since it runs only at 1Hz). There are lots of examples coming with LabVIEW showing good practices.
