We had house leaks and needed to continue to monitor the moisture level in the wood (ceiling) and drywall. My home inspector recommended this one as an inexpensive alternative to his $400+ Surveymaster moisture reader. However, this device was so inaccurate that made me doubt its usefulness.

Off the dry wall, when the reading from Surveymaster was 22%, this one's was 15%. Two locations off the ceiling wood, Surveymaster vs. Sonin were 18% vs. 8%, and 12% vs 8%. All the readings were done on the same day by my experienced home inspector who used the devices in the exact same location w/ exact same direction (when pining into the ceiling) and tried to use the same force to minimize the error bar caused by mishandling.

Sonin's readings were the same 8% even though there was a 10% difference in the readings from Surveymaster. 8%-12% would be considered ok for wood, but 18% is not. For example, mold remediation company would dry the ceiling wood below 16% before they put on the final coat. W/ such inaccuracy, I found it nearly impossible to have a good assessment on the situation and to take necessary actions.

Another drawback of the product: the pins are not sharp at all comparing to the Surveymaster's. In test, the pins couldn't penetrate into some plywood area under the roof, and hence couldn't get any readings.

In short, it is cheap for a reason. Use it w/ bucket load of grain of salt.
We had house leaks and needed to continue to monitor the moisture level in the wood (ceiling) and drywall. My home inspector recommended this one as an inexpensive alternative to his $400+ Surveymaster moisture reader. However, this device was so inaccurate that made me doubt its usefulness. Off the dry wall, when the reading from Surveymaster was 22%, this one's was 15%. Two locations off the ceiling wood, Surveymaster vs. Sonin were 18% vs. 8%, and 12% vs 8%. All the readings were done on the same day by my experienced home inspector who used the devices in the exact same location w/ exact same direction (when pining into the ceiling) and tried to use the same force to minimize the error bar caused by mishandling. Sonin's readings were the same 8% even though there was a 10% difference in the readings from Surveymaster. 8%-12% would be considered ok for wood, but 18% is not. For example, mold remediation company would dry the ceiling wood below 16% before they put on the final coat. W/ such inaccuracy, I found it nearly impossible to have a good assessment on the situation and to take necessary actions. Another drawback of the product: the pins are not sharp at all comparing to the Surveymaster's. In test, the pins couldn't penetrate into some plywood area under the roof, and hence couldn't get any readings. In short, it is cheap for a reason. Use it w/ bucket load of grain of salt.