ML1500 Analog Smoothing

[mhowasso 5]

Hi All, Im sure this has been covered before... Im using a ML1500 and a 4-20ma output flow meter. Due to the erratic flow in the line the analog signal is all over the place. What is the best way to smooth this signal out so I don't see all these variations..??? I don't have a CPT instruction on the ML1500 but there has to be a way. Just looking for the way you guys do this that gives you the best results. Thanks

[Mickey 71]

See text. Just do the math three instruction "SUB" then "MUL" then "ADD" Filtering.txt

[mhowasso 5]

Thanks Mickey Just curious...are there are any other methods also..?? Edited 6 Aug 2014 by mhowasso

[b_carlton 61]

Just as a note, an unavoidable side effect of the smoothing is the time delay in seeing the FULL effect of a real change. So be very careful with the multiplication factor, just enough to get the amount of smoothing you need. Start from .99 and work down slowly. Edited 6 Aug 2014 by b_carlton

[mhowasso 5]

Will do. Thanks

[Mickey 71]

Some flow transmitters will have a build-in filter(smoothing). Depening on the analog input card you have they also have filters. See thier manuals. Edited 6 Aug 2014 by Mickey

[mhowasso 5]

Just so Im clear on this... FV = FV + C (NV - FV) Where: F V = Filtered Value (F8:0) C V = Constant Value (F8:1) (range 0-.99) The smaller the number the more dampening. N V= New Value (F8:2) F8:0 = (F8:0 + (F8:1 x (F8:2 - F8:0))) F8:2 - F8:0 = F8:3 F8:0 = (F8:0 + (F8:1 x (F8:3))) F8:1 x F8:3 = F8:4 F8:0 = (F8:0 + F8:4) F8:0 + F8:4 = F8:0 Is the FV FIltered Value F8:0 my original non-smoothed signal OR my new smoothed signal..??? Is the NV New Value F8:2 my new smoothed signal OR my original non-smoothed signal..??? When you label it as New I just assumed it is the smoothed value. Thanks for your patience in advance..!! I apologize if Im making this more complicated than it is. I just want to do it right. Edited 7 Aug 2014 by mhowasso

[Mickey 71]

FV is the filtered value ( smoothed signal) NV is the unfiltered value ( original non-smoothed signal) Edited 7 Aug 2014 by Mickey