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Jesse posted an update 5 years, 3 months ago

Hi,
I’m excited to be a part of the forum. Let me kick things off with an anomaly! I have a Mayfly with a gauge sensor and I went to go collect the data and clean the probe. When I sat down to look at the data, I was getting negative readings. It was fine and then the depth got lower and lower and then suddenly went negative. Has anyone had this problem before???
- neilh20 replied 5 years, 3 months ago
  
  Hello Jesse, great you joined.
  Can you need to provide a bit more information.
  It is **normal** ~ though perhaps undesirable and non-intuitive ~ for a depth measuring instrument to show a slightly negative depth when outof water. Depending on the type of physical sensor they don’t know 0.0 – they have to be calibrated for it, and even that, unfortunately can drift,
  When there is a need to measure low stream flows, what I do is make sure the sensor is in a “pool” of water up stream of the flow measurement place. I try and make sure that the sensor is capable of measuring at least a couple of inches of water depth before the water flow dries up.
  - Jesse replied 5 years, 3 months ago
    
    Hi Neil,
    Thanks for your reply! This sensor is submerged deep in a pool. After I saw that it had a negative reading, I cleaned the outside of the probe, put it back in the water, and took another reading and same thing, negative numbers. Some I’m not sure what to try.