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.

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.

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.

Love this product checks all our wood we buy for our fireplace

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!

Works great

This moisture meter has been extremely helpful and easy to use. I used it to check different areas near the wall and floor, and it provided clear and consistent readings. You can immediately see the moisture level on the screen, which makes it very convenient for quick inspections. The device feels solid and well made. It responds quickly and gives accurate results, which is especially useful for detecting hidden moisture problems before they turn into bigger issues. I like that it has different indicators, so it’s easy to understand whether the moisture level is low, medium, or high. Overall, this is a very practical tool for homeowners. It helped me better understand the condition of my floors and walls, and I’m glad I had it on hand. I would definitely recommend this product to anyone who wants a reliable and easy-to-use moisture detector.

I recently noticed a small crack in my ceiling that has a large brown outline around it. The brown outline is clearly water damage, but while the crack is definitely new, I cannot tell if the water damage has always been there or not. I bought this device to help me to determine if I need to call in a professional. The product arrived today, as expected. It was in its retail packaging, which is a clamshell. You'll need scissors to open it up. A 9v battery was also inside the clamshell. I'm not sure why the change, but I'm really happy that companies are now including batteries with their toys. So I took the meter out of the packaging and put in the battery. No screws to take out or anything. The battery cover just clips back on. The device couldn't be much easier to use. There are only 3 buttons.. 1. Power. Hold this to turn the moisture meter on and off 2. Mode. Press this to switch between wood and "construction material" mode. 3. Lock/Sound. Press this toggle "lock" of the display in case you want the percent to stay on the screen. Hold this to toggle whether or not the device beeps (you probably don't want it to beep). I'd be testing my drywall ceiling, so I put the moisture meter into "construction material" mode. I was hoping I wouldn't need to jam it into my ceiling to see the results, so I first tested a part of the ceiling I knew did not have a leak. The meter read about 3%. I moved over to the brown spot and pressed the needles against the ceiling (I didn't push in) and, depending on where I was along the brown spot, the reading ranged from about 2%-6%. According to the guide on the back of the device (which is great), this means my ceiling is not very moist. Obviously that was good news. Then I started to worry that the device would not function right if it wasn't fully pushed into the ceiling. I really did not want to put holes in the ceiling, but I figured that in the best case, I'd need to paint over the brown spot anyway, so two little holes couldn't hurt. So I jammed the needles into the ceiling in a few places and getting a consistent reading was not easy. In a few of the spots, the percentage changed from between 1%-2%, then from 7%-10% and back again. I wasn't moving the meter -- it just could not decide the moisture level. Now, I understand the science behind the device (at least I think I do), so I get that I could have been moving it a little or maybe I was there was some movement within the ceiling so the circuit was not continuously completed.. I'm really not sure. I tried a few different places in the ceiling, and in the end, I have slightly more confidence that there is not a leak on the ceiling, but I am not sure about it. Hopefully if there was a leak, the device would be more decisive in telling me about the moisture. Overall, I think I'm happy about the purchase, but only because I got a little extra confidence for $30, which is probably less than I would have paid an "expert" to come and check it out. If you're a home inspector or contractor who will be charging people for your use of a moisture meter, I would look into the more expensive options, but for a homeowner who does not want to pay $100+ for a device you'll probably use 2-3 times in your lifetime, this one will give you a little more information than you currently have. In summary, very easy to use, but I'm not completely confident in its ability to give reliable results.

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

Easy to use with timber

I bought this gauge mostly to check if firewood is dry enough to use in our wood heater. It works great for that purpose, but it seems the manufacturer designed it to show if construction materials are dry enough to use without risk of mold occurring. I expect it would work well for that as it is easy to use and easy to read the display. An added bonus in this price range is the calibration contacts in the cap. You can check it before you use it, to make sure it is reading accurately.

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.