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--- atmos:instruments:wcm:home [2025/05/07 18:04] – rickbeil
+++ atmos:instruments:wcm:home [2025/05/07 19:26] (current) – rickbeil
@@ Line 3: / Line 3: @@
 ===== Problem (Spring 2025) =====
-When water droplets go from being present to not being present over the probe head there is a noticeable decay in the data which causes a negative exponential graph to be present. This then results in an indication that water droplets are supposed to be present even though there are no droplets passing over the probe head during this decay period of time. Attached below are photos and graphs that better visualize the problem that is present while using the WCM probe.
+==== Introduction ====
+During the use of the WCM it was noticed that when compared to other instruments such as the Cloud Droplet Probe, RICE probe, and the hot wire boom probe there is a decay present after the water content should have gone to zero over the probe head. This is now something that is being lab tested to better understand what is going on with the probe and to try and correct this invalid data that is being collected. Below are references to where the data is located for this particular lab run.
   * Reference: /nas/und/NorthEast/2025/Lab/CH423/GroundData/20250416_165626/PostProcessing
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 Below is a side by side comparison of what was recorded during this test by both the probe head and the video which in the video shows when water droplets are present and when they aren't. The graph is also marked as to roughly where the video is showing data at and where the corresponding area is on the graph.
+==== Video Comparison ====
 {{:atmos:instruments:wcm:16_59_59_water_on.jpg?400|}} {{:atmos:instruments:wcm:wcm_water_off_graph_m-300_16_59_59.jpeg?400|}}
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 {{:atmos:instruments:wcm:17_00_02_water_off.jpg?400|}} {{:atmos:instruments:wcm:wcm_water_off_graph_m-300_17_00_02.png?400|}}
-===NOTICE===
+==== NOTICE ====
 One thing to note with the data displayed in the graphs is that the zero baseline is at 2.2 instead of being at zero. This is another noticeable issue with the M-300 and the way it records data. I will refer to this baseline as 'zero' in the rest of the analysis.
 ==== Analysis ====
-The delay between when the WCM displays a 'zero' value and when the probe should be at 'zero' is around about a five or so second delay which can be observed by the graphs. Which after applying a 66.7% data validity factor to the delayed seconds this comes out to being about a 3.34 second delay where data is being displayed that shouldn't be. This is of course just one case but, during this particular data set I did a few other runs where I would run a minuet without water and then a minuet with water.
+The delay between when the WCM displays a 'zero' value and when the probe should be at 'zero' is around about a five or so second delay which can be observed by the graphs. Which after applying a 66.7% data validity factor to the delayed seconds this comes out to being about a 3.34 second delay where data is being displayed that shouldn't be. This is of course just one case but, during this particular data set I did a few other runs where I would run a minuet without water and then a minuet with water. Below are the other runs that I did which all show this similar decay that occurs right after the water is cut off from flowing over the probe head.
+==== Decay Graphs ====
+{{:atmos:instruments:wcm:wcm_graph_17_02_00_m-300.png?400|}} {{:atmos:instruments:wcm:wcm_graph_17_04_00_m-300.png?400|}}
+{{:atmos:instruments:wcm:wcm_graph_17_06_00_m-300.png?400|}} {{:atmos:instruments:wcm:wcm_graph_17_08_00_m-300.png?400|}}
+Top left - 17_02_00 Graph, Top right - 17_04_00 Graph, Bottom left - 17_06_00 Graph, Bottom right - 17_08_00 Graph
+Each graph is marked at roughly where the video indicated no more water being present over the probe head.
-This data will be added soon.
+The way that I determined the delay interval was by determining that each tick on the graph is roughly one second of data and then counting the ticks it took to get to a baseline value. The way I determined this baseline was by observing where the data mostly stabilized at so this is mostly subjective in terms of determining this value. But I mostly settled on a value of at or below 2.2 on the x-axis. The corresponding values that I then found for each graph are as follows; 6 seconds for 17_02_00, 6 seconds for 17_04_00, 5 seconds for 17_06_00, and 7 seconds for 17_08_00. This then came out to be an average of 6 seconds of data present during this decay. Then after applying the 66.7% validity to this average I found that there is about 4.00 seconds of incorrect data during these runs.
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 During the setup of the WCM, we were having issues with the power not being supplied to the WCM Power Box which prompted the WCM software to say that ser17 can't open.
-===== Cause =====
+==== Cause ====
 The power connection of the leads from the WCM Power box to the D/C Power supply was not making a good connection with the prongs themselves on the D/C Power supply.
-===== Solution =====
+==== Solution ====
 The leads coming from the WCM power box where squeezed together to help in making better contact with the prongs on the D/C Power supply.