Answer to sTEm–at-Work Puzzle #41: Olde But Goody Series Water Filter Performance Test

The Problem: Olde But Goody Series Water Filter Performance Test


Analysis: 
This is an opportunity to show students that if they can interpret the information from a graph with two lines, the can also deduce the blue plot has higher flow values than the orange plot at every pressure value. Thus, with the clues provided in the puzzle statement:

If the filter is not clogged, the back flush test pattern has a similar shape as the forward flow plot, but the back flow data indicates higher flow rate values for each pressure.

She has determined that this specific filter (is not clogged) it follows that the statement: "the organe plot is the filter's back flush data plot" cannot be true.

The puzzle also acts as a lead in for a discussion about preferred directional flow. In this case, based on (II) above, the structure of the nono-tube based membrane makes it easier to push water through the membrane from the purified water side than the non-pure water from the other side.



Question
The orange plot is the filter's back flush data plot. Yes or NO

Answer: NO