The unit bought October 2014 made a good impression so far, in particular because of the reproducibility of the values at the same measuring point. So far everything well! Since October 2014 I measure monthly progress during drying my wet basement wall at 40 measuring points and note the declining readings. Today suddenly consistently about a doubling of the display values at all measuring points, as if the drying wall suddenly become soaking wet (eg in Point 3: last measurement: "28", today's measurement "63"). Then I had a terrible suspicion: Perhaps today's battery change was because of something dark that have become the cause of LED lighting. And so it was! Plugging the old battery showed the expected low values. From my perspective, there is a design defect if low battery measuring is not prevented and no warning will be displayed before low battery condition. Should I use a non-tolerable measurement deviation even at usual slight deviations from the ideal state of the battery voltage detect 9 volts the unit will go where it belongs then: In the container for waste.
