Posted: 07/06/2016 at 11:48
I've got the same model and it gives a good reading for moisture. Like Ladybird says it's better to use a soil testing kit rather than a monitor.
All monitors need regular calibration if they're to be trusted. The easy way is to check your meter against 3 preset soil types, ie dry, moist and wet. If it gives a corresponding result you can have confidence in its readings.