Moisture meter – mobile home & house

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A moisture meter for detecting moisture penetration or leaks in the motorhome or house helps to prevent damage in good time.

If a water stain has already formed on the visible wall or ceiling cladding in the motorhome or caravan, or even mold, the damage has already occurred. If you want to become aware of penetrating moisture in good time, a suitable measuring device is helpful. The necessary investment saves you major financial damage and work, so it pays for itself in next to no time.

Regular inspections of the cupboard areas adjacent to the outer wall/ceiling only take a few minutes, in contrast to workshop visits that often last days and are costly to repair moisture damage.

Theory of moisture measurement of building materials

Humidity measurement with a hygrometer is common. Here, the 2.5 percent expansion of a human hair, or even a synthetic fiber, in the range of 0 ... 100% rel. humidity is transferred to a pointer mechanism and displayed in analog form.

Two methods are mainly used to measure material moisture: the invasive conductance or non-invasive dielectric method.

Conductance method - resistance measurement

These devices can be recognized from the outside by the two measuring tips on the front. By piercing the material to be tested, the increasing resistance with increasing moisture in the material is evaluated and digitally displayed.

The advantage of this method is the simple, fast recording of measured values and the uncomplicated setup of the measuring electronics. The disadvantages, however, are the limited accuracy, the stitch marks in the material and the need to take the exact material parameters into account in order to evaluate the measured values accurately.

Dielectric method - capacitance measurement

Here too, the measuring sphere, which is common to all devices using this measuring method, is either attached directly to the device head or mounted via an extension. It consists of a dielectric (non-conductive layer) between two electrically conductive surfaces to which a voltage is applied, creating an electric field. The change in this field (the dielectric constant) due to the presence of moisture is evaluated and displayed digitally. Air has a dielectric constant of 1, water 80, so if the device displays 56, for example, it can be assumed that there is a leak (e.g. in a pipe in a house) or that rainwater is beginning to soak a wall in a mobile home.

The advantage of this measuring method is the non-destructive measurement, a very wide measuring range with high accuracy and stability, fast value determination and high resistance to chemicals.

The disadvantage is a lower accuracy in ranges < 5% rel.F. and the higher electronic complexity of the preparation of the measured value to be displayed (higher demands on the entire value recording and value processing chain).

The price question

I'll just take a quick measurement ... - a lot of crap, applies to devices that are offered in the lower two-digit euro range. Neither the accuracy of the measured value nor the repeatability provide useful results. Your own finger is more sensitive and more precise in sensing moisture.

You guessed it: it costs again. But far less than repairing moisture damage!

In the affordable ranges, the FLIR MR59^TM stands out from the variety of offers with a balanced price-performance ratio. Unfortunately, the device will not be available again until the end of Q3 2024.
The demand seems to underline the quality of the device, regardless of the weather, which is also confirmed by the manufacturer's three-year factory warranty.

An integrated LED illuminates the measuring area, and the sensor ball mounted slightly away from the housing also enables measurements to be taken in hard-to-reach places.

Bluetooth BLE (Bluetooth Low Energy) connectivity also enables the measured value display to be detached from the device. Min/max functions, including data hold, round off the performance spectrum nicely.

The data sheet has a measuring depth of 100 mm, which is a pleasant contrast to the maximum 40 mm usually offered by cheaper devices.