General Tools MMD4E Moisture Meter for Wood, Walls & Water Leak Detection

We were getting hardwood floors installed - or so we thought - when the installers notified us that they could not do the installation because the wood in our house had acclimated to 6.4% moisture and our subfloors were at 12.8% moisture. The installer found a leak in our water softener line which we got fixed the next day. Unfortunately, we had no way of knowing (ourselves) when to call the installer back. Hence, we purchased this meter. As far as we know, it works great. We aren't too concerned with the overall accuracy of the instrument, +/- 3% is just fine for us as we're looking to compare the difference between two materials in our home (assuming the error is consistent between those readings). The resolution of the meter is 0.1%. Other things you might want to know: - It comes with it's own 9v battery. - It measures wood between 5 - 50% and 1.5 - 33% for other building materials. - It has a hold feature which allows you to save the current reading so you don't have to keep the meter jammed in the material you are measuring. - It beeps to let you know when it is done measuring. (Although, you can turn this off. We did accidentally and then figured out how to put it back on. We don't know why, but it has 8 different tones from which you can select.) - It has a toggle button between measuring wood and concrete (or other building materials). - The instruction manual is easy to read and follow. They come in English, French, and Spanish. - It uses a two pin system to measure the electrical resistance of the material between the two pins. This is then calibrated against moisture content to give you the reading as a percentage. This means that it will make two small pin holes in the wood you are trying to measure. Therefore, if you are concerned about the holes, consider a "pinless" moisture meter, which are much more expensive. The instruction manual lists other uses such as testing the moisture content of powders (for any scientists out there who need to measure such things for making standard solutions from scratch) and to test the dryness of a wall or furniture before painting or finishing. It also shows instructions for how to track down a leak using the meter. There's a funny picture in the instructions with the caption "be careful not to hurt your hands on the pins." Although, I did "test" the moisture content of my husband's leg. Don't worry, I didn't draw blood. Overall, for the price, the features, and the product functionality (so far), I would say this is a great buy. Also, we got it shipped quickly via Amazon.com. It arrived two days after we purchased it. Yay! UPDATE (7/31/2010): The pins broke when we were testing some brazilian walnut - one of the hardest woods out there. But I read in the instruction manual that pins were replaceable. I emailed General Tools through their website and got a quick email back. Less than a week later, I had two new prongs FOR FREE in my mailbox. Customer Service was AMAZING! The replacement prongs are much better than the ones that came with the meter. The new ones are shaped like little cones and have worked great on the harder woods.

Very handy; somewhat easy to use. Gave me a lot of information that I was looking for...I am not happy finding high moisture levels on some wood and some sheetrock; now I need to determine where the moisture is coming from.

This moisture meter was really easy to use. It includes a cover, and extra set of needles. I did notice that sometimes the meter resets or cant read if its pointing straight up like at the ceiling. Super lightweight and easy to use.

This is a great product for the price. Amazon got this to me in a timely manner. My general reason for buying this item was to measure firewood. As far as I can determine, it is very easy to operate, functions as stated, and I believe I made the correct choice for my purposes. I will state here that I did not read all of the reviews, but I read enough of them to decide upon this item. These are my technical observations for those who may have doubts reading some of the other reviews. I wondered about the battery life, so I made some checks. Using my Heathkit IM-2215 digital multimeter, I found that the current draw in the on (no measuring) position using the 200 ma scale, was a steady 5.8 ma. Using the lowest scale of 2 ma, the current draw was 5.8 ma with a fluctuating least significant digit (LSD). In the off position, using the lowest 2 ma scale, I note a current draw of .000 ma. So, my dear friends, if there is any current draw, it would have to be in the micro-ampere range. It probably draws less than my digital clock in the car! I am not worried about the battery life. If you doubt these studies, let me inform you that I have been a licensed radio amateur since 1962. Trust me, I know what I'm doing. Depending on the species of wood, most woods (previously kiln dried) will absorb in a humid environment, in the neighborhood of no more than 13 to 14 % moisture. I got this information from my local lumber producer. I looked at numbers worked out with a formula. I found that interesting, so I probed some timbers down cellar in this nearly 100 year old home. Wood posts and floor joists showed some variation, but in general were 13 to 14 % moisture in my cellar having a humidity level of 80 to 90 percent. My highest joist readings were 15.9 and 16.0 per cent. I have one of those Acu-rite digital devices on the cement floor. The temperature was 61 degrees. The upstairs humidity is currently running at 58 %, which is not ideal. I have been considering a dehumidifier. I hope this information allays any fears you may have purchasing the MMD4E moisture meter. I love it!

Worked well to confirm studs were dry after a water leak. Measurements agreed with those taken by testing lab who took samples to confirm no mold was present.

The General Tools MMD4E Digital Moisture Meter is an indispensable tool for anyone dealing with moisture-related issues. From the moment I started using it, I was impressed by its accuracy and ease of use. Whether I'm checking for water damage in walls, floors, or ceilings, this moisture meter provides precise readings with just the press of a button. What sets the MMD4E apart is its versatility and reliability. It features a wide moisture detection range, allowing me to accurately assess moisture levels in various materials, from wood and drywall to concrete and plaster. Plus, its compact size and ergonomic design make it comfortable to hold and use for extended periods. Overall, the General Tools MMD4E Digital Moisture Meter is a must-have tool for contractors, homeowners, and DIY enthusiasts alike. Its accuracy, versatility, and ease of use make it an invaluable asset for identifying and addressing moisture issues quickly and effectively. I highly recommend it to anyone in need of a reliable moisture meter.

I have this 3 stars but not for use, as I can’t even get the battery cover plate off in order to do so! It looks easy and standard, but it does NOT come open. I needed it asap and ordered with overnight delivery so it’s disappointing I can’t even use it. There is also NO manual. So I referred to the product info via Amazon and the products additional info- mainly to figure out if there was some magic to opening the battery compartment. Unfortunately, the online instruction all say to refer to your manual as models can be different. (This is noted for every single instruction) I feel this is overpriced as it’s feeling very cheap at this point. It would be nice to actually use it. I think I will need to break the battery cover open and duct tape it back after putting the battery in it.

I think it works pretty good I use it for RV checking and it seems to be pretty reliable I don't know the actual accuracy because I can't check it against something else yet but it works and it'll give you peace of mind

It's the best from all th meters available in market

Easy to use with timber

Very useful and we found something not new damage in the wall we can’t see it but with this we discover it .

Excelente artículo y servicio. Muy fácil de usar.

Die Funktion ist einfach und gut ablesbar, doch eine Beschreibung ohne deutsch ist schlecht zu gebrauchen. Das gesamte Ergebnis ist aber gut.