I am trying to understand the rate of flow decline of water filters over time. It appears the filters work fine for an extended period of time, then suddenly decline in flow rate between 3 and 4 months. I need to track, record and graph the performance and fall off of the flow rate over time.
so, I have the dates the flow rate was measured (random dates) for several filters and the exact flow rate,. The flow rate is a single number, the number of seconds to flow 32 ozs. So, for multiple filters I have the dates they were checked, the flow rate for those dates. The number of days is calculated from day 0 (day new) to date of each measurement. The starting dates are not the same for any filter/data set, so days is the key time component representing time in service.
ex: Filter 1 0 days(new) = 21.05 sec.
45 days = 28.35 sec
60 days = 29.56 sec
105 days = 30.39 sec
119 days = 58.51 sec
Filter 2 0 days(new)= 23.82 sec
82 days = 27.53 sec
105 days = 29.65 sec
What I need to display is a line graph with this data (and several more sets of data) with the elapsed time across the horizontal axis and the flow rate (seconds) on the vertical axis. Purpose is to demonstrate visually the rapid fall off of efficiency of flow rates in the 100 to 120 day range. I would like to have one line for each filter. And I need to maintain the total elapsed number of days to show the sudden and dramatic drop off in the last 30 days.
So, any help you can give on how to graph this data would be appreciated. I am open to the structure of the data as I haven't entered much data at this point. I want to get it right before adding a ton more data.
Thanks in advance for any help you can provide.