Yujuyo,
Made in china MD is very hard to used in terms of knobs setting before I have one and I test it in my training site with buried of copper and aluminum in a different sizes and depth but no any target detected even the shallow depth.
I have Nokta Golden King NGK and DPR, TM808 with IconData Logger, V4 Pin pointer, LRod with Power Module, Geo Examiner standard equipment and also in my custody the Double Magnum, GPL and Minelab GPX5000. All equipment that have 3D Image are need a good data analysis or interpretation that is why the newbie for this equipment always mis-interpret it, if the the image on 3D show a target and dig it and the actual is nothing then he say it is bad equipment but the truth is a false target only they got. Some of 3D Image have Data Value or Soil Data ( I don't know the term used in other 3D software) score and it should be high value need for a true target and always repeat the scan as many you can then the average or the consistency of detection can say that is a true target. But not the end you can used another scanner or detector to verify if it same result. Same with the Doctor that say you have a cancer and you need a second opinion to the other Doctor before you can say that you have a cancer.
vourvon