FI108891B - Method and apparatus for measuring the moisture in structures - Google Patents

Description

108891

Method and apparatus for measuring structural humidity

The invention relates to methods according to the preambles of claims 1 and 4. The invention also relates to a measuring unit according to the preamble of claim 6 and a measuring device according to the preamble of claim 10.

Methods and devices of this kind are used to measure structural humidity inside structures. Structural humidity is measured, for example, on a wall, floor, ceiling or floor. The structural material to be measured can be, for example, concrete, wood or thermal insulation. Humidity can be measured either momentarily or by monitoring the evolution of humidity 10 as a function of time. Instantaneous moisture measurements can be used to determine the moisture content of the structure, for example for moisture damage analysis. As a function of time, moisture can be measured, for example, to monitor the drying of a structure, such as a concrete slab, during construction, water damage, repairs or long-term structural monitoring of structures.

According to the prior art, the humidity of the inner parts of structures has been measured by drilling a hole in the structure and measuring moisture through this hole. Drilling requiring ;;; understandably there are several problems with the implementation of measurements, such as. the need for drilling equipment and the risk of damage to structures and piping embedded in them. This problem is solved in U.S. Patent No. 5,730,024, which discloses a probe to be embedded in a structure during the construction phase. The probe comprises a waterproof but vapor-permeable protective housing with humidity and temperature sensors inside. The humidity sensor is a hygroscopic body embedded in: V: two electrodes. The probe further comprises electrical conductors to the outside of the structure to be measured from the probe and means for attaching the probe to the structure to be measured. Moisture measurement is based on those in the hygroscopic body; '' ': For measuring the resistance between electrodes from outside the structure:. via electric wires. Such probes are to be installed in structures · “. in their construction phase. The probes are placed at suitable locations, e.g.

inside the concrete slab. Measuring sensors are thus permanently placed in structures. The actual 2 108891 measuring device does not need to be connected to the structure to be measured, but can be connected to the sensors via electrical wires for the duration of the measurement.

A drawback of the prior art is that sensors have to be placed in the structures along with the probes. This entails significant costs, since in order to achieve comprehensive s measurement readiness, it may be necessary to install several separate probes at each construction site and thus also numerous sensors. If moisture is detected in the structure, it is usually necessary to verify the accuracy and accuracy of the measurements and sensors before disassembling and wrecking the structures. This is not possible with fixed sensors 10.

The object of the invention is to eliminate the above-mentioned drawbacks and to provide a completely new method and device for measuring structural humidity.

The invention is based on the fact that only a measuring channel is placed in the structure where the necessary sensors can be placed during the measurement. The measuring duct consists of a vapor-impermeable tube, the first end of which is placed at a point to be measured inside the structure and the other end extends to the surface of the structure. The other end of the measuring duct extending to the surface of the structure is closed by a tight plug. A vapor-permeable plug may be provided at the first end of a measuring channel inserted into the structure. The measuring device, in turn, comprises a measuring unit and the ': 20 temperature and humidity sensors and a second temperature sensor connected thereto. When measuring moisture '; '·' The plug that closes the other end of the measuring channel is removed and replaced with a temperature and humidity sensor. The second temperature sensor is pushed along the measuring channel. . to the first end of the measuring channel. Humidity and temperatures are measured after the moisture profile * · * has stabilized in the measurement channel, and the results are used to calculate the equilibrium humidity around the first 25 ends of the measurement channel.

t * | More particularly, the methods of the invention are characterized by:. as set forth in the characterizing parts of claims 1 and 4. For the invention: '; the measuring unit, in turn, is characterized by what is shown in the characterizing part of claim 6 and the measuring device is what is described in the characterizing part of claim 10.

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The invention provides considerable advantages.

When using the invention, it is not necessary to permanently place sensors inside the structures. Thus, tracking the measurement capability of the invention to structures becomes considerably advantageous. Because the same sensors can be used in many different S measurement sites, it is economically feasible to use higher quality sensors in the context of the invention.

A further advantage of the invention is that, for example, routine moisture damage screening measurements can be made with a cheaper measuring device, and if moisture damage is detected, it can be analyzed by a more accurate method through the same measuring channel 10.

The invention will now be illustrated by way of example and with reference to the accompanying drawings.

Fig. 1 schematically shows one measuring channel according to the invention mounted in a structure and one measuring device according to the invention connected to it.

Figure 2 schematically shows a second and a third measuring channel according to the invention: and a second measuring device connected to a second measuring channel according to the invention.

Figure 1 shows the structure 1 to be measured, the measuring channel 2, 3, 4 embedded in the structure and the measuring device 5, 6, 7, 8, 9 connected to the measuring channel 2, 3, 4. roof structure. Embedded in structure 1. · 20 measuring channels 2, 3, 4 comprise a steam pipe 2, a measuring box 3 extending from the second end of the steam pipe 2 and a protective plug 4 fitted to the first end of the steam pipe 2. to the measuring unit 5 through a vapor barrier 6. . ·. connected by a conductor 8 and a humidity and temperature sensor 7. The measuring device 5, 6, 7, 8, 9 comprises: 25 also a second temperature sensor 9 attached to one end of the conductor 8.

.; Figure 2 further shows a vapor barrier plug 10 which closes one end of the steam guide 2 and a cable 12 connecting the probe 11 and the probe 11 to the measuring unit S '.

108891 Steam conduit 2 is mounted to structure 1 with the first end of the conduit 2 within the structure 1 near the desired measurement area and the other end extending either to the surface of structure 1 or, when using the measurement box 3, to the bottom or sidewall of the measurement box 3. The function of the steam guide 2 is to act as a diffusion path through which any moisture in the structure 1 at the first end of the steam guide 2 is diffused to the other end of the steam guide 2. Hereby, the moisture of the structure 1 can be measured from the other end of the steam guide 2 brought to the surface of the structure 1, and expensive measuring cabling extending to the first end of the steam guide 2 is not required. The vapor guide 2 is made of a suitable tube or tubular body made of a substantially vapor-tight material. Further, the material of the tube is preferably inexpensive and mechanically resistant and can be easily bent to a suitable shape. One preferred material for making the steam guide 2 is a plastic interior installation tube commonly used for indoor installation of electrical cables.

As an extension of the other end of the steam guide 2, a measuring box 3 can be fitted, which is mounted on the surface of the structure 1. The use of a measuring box 3 is not necessary, but it may facilitate the measuring process. The function of the measuring box 3 is to act as a rack into which j; the measuring device 5, 6, 7, 8, 9 for measuring structure 1 is fitted. Thus, the measuring box 3 and the measuring device I: 5, 6, 7, 8, 9 are shaped to be mutually matching. Measuring box 3! * I # ', ·· 20 also protects the other end of the steam guide 2. A removable vapor barrier plug 10 (Fig. 2) is disposed at one end of the steam conduit 2 in addition to the measuring container 3, the function of which is to prevent moisture from being transferred from the conduit 2 to the ambient air or vice versa. The other end of the steam conduit 2 is kept closed by the vapor barrier plug 10 whenever the conduit 2 is not used for 25 measurements. If the vapor barrier plug 10 is not used, the moisture possibly present in structure 1 can be evaporated locally to the first end of the vapor guide 2 ;;; ' The humidity values measured from the environment and from the steam conductor 2 no longer represent the humidity situation generally prevailing in structure 1. The vapor barrier plug 10 is used for both

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: ··: with measuring box 3 with or without steam box 3 installed with steam guide 2 '· · * 30.

108891 In turn, a protective plug 4 is provided at the first end of the vapor guide 2. One purpose of the protective plug 4 is to prevent the building material in the structure 1 from penetrating the vapor guide 2. It is particularly important to use the protective plug 4 when casting the steam guide 2 into concrete. However, in some cases, for example when inserting the steam guide 2 into a hole drilled in the wood, it is not absolutely necessary to use the protective plug 4. The plug 4 must be permeable to water vapor. The protective plug 4 can be made of, for example, a slender and dense wire mesh, wood or water vapor-permeable plastic.

The measuring unit S contains the necessary electronics for controlling the humidity and temperature sensor 7 and for the second temperature sensor 9 and for processing the measurement results.

Preferably, the measuring unit 5 is housed in a housing whose appearance conforms to i! the shape of the interior of the measuring box 3 so that the measuring unit 5 can be easily placed | | measuring box 3 to a preferred measuring position. This means e.g. such that the vapor barrier 6 and the humidity and temperature sensor 7 are then automatically positioned correctly at the mouth of the steam conduit 2 15. Alternatively, the measuring device may also be implemented such that the measuring unit 5 'is not designed to be placed directly in the measuring box 3 (Fig. 2). In this case, a separate: probe 11 is connected to the measuring unit 5 ', which is placed at the mouth of the steam conductor 2, e.g. the cable 12; Γ: via. A vapor barrier 6 is associated with the measuring unit 5 or the separate probe 11.

• V ·· 20 The function of the vapor barrier 6 is to isolate the other end of the steam conduit 2 from the environment during measurement. The vapor barrier 6 can be made, for example, of rubber. The humidity and v. 'Temperature sensor 7 and the second temperature sensor 9 are selected from suitable sensors' · ''. The temperature sensor 9 is preferably selected so that it can also supply thermal power to the environment if desired. The temperature sensor 9 thus preferably functions as both a heating and a measuring resistor.

* * *. . ·. In the method of forming a measuring channel, an elongate measuring channel 2 is formed in the structural material 1 having first and second ends and bounded by * «·; ·, Between the first and second ends of substantially vapor-tight material.

, ···. The measuring channel 2 is preferably formed in connection with the formation of the structure 1 I · · 30 by placing, for example, an indoor installation pipe in the structure. For example, in the case of a concrete structure, this can be done by placing 6 108891 one or more suitably placed indoor installation pipes in the casting area before pouring the concrete. The measuring channel 2 is shaped such that its first end remains inside the structure 1 and the other end extends to the surface of the structure 1. The first end of the measuring channel 2 is preferably protected by a vapor-permeable protective plug 4. Thereafter, the structure 1 may be closed or, in the case of a concrete structure, the concrete slab may be cast. The other end of the measuring channel 2 is suitably shaped and sealed by a vapor-impermeable vapor barrier plug 10. A measuring channel 2 is formed in the structure 1, along which the moisture content within the structure 1 around the first end of the measuring channel 2 can be led to the other end.

10 In the moisture measurement method, the vapor barrier plug 10 which closes the first end of the measurement channel 2 is removed and the temperature sensor 9 is inserted into the measurement channel 2. The temperature sensor 9 is inserted along the measurement channel 2 at least approximately | to the first end of the measurement channel 2. The temperature sensor 9 can be pushed, for example, by means of a conductor 8 connected to the sensor 9. Subsequently, the humidity and temperature sensor 7 is inserted into the measuring channel 2, and the measuring channel 2 is substantially vapor-tightly closed by a vapor barrier 6. Alternatively, the humidity and temperature sensor 7 can be positioned at the mouth of the measuring channel 2 and form a vapor barrier 7 around. Temperature sensor 9 and humidity and • 1 I> «·. ':. the temperature sensor 7 is connected to the measuring unit 5.5 '.

»* • · * * · '; 20 After placing the measuring device in the measuring channel 2, it is expected that the operations. , the moisture profile of the measurement channel 2, possibly disturbed, is leveled by diffusion »i ·» · »!.! the influence. The settling time is typically about one minute per cm * of length of the measurement channel * * · 2. After the equalization time the temperature sensor 9 is measured! , v, the temperature T of the first end of the measuring channel 2, and the humidity and temperature *> · • »: '. By means of the sensor 7, the temperature T2 and the relative humidity Rh2 of the other end of the measuring channel 2 are provided. If the temperatures T1 and T2 differ, the relative humidity Rh2 measured at one end of the measuring channel 2, <··, does not directly represent the relative humidity Rh1 at the first end of the measuring channel 2.

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'.V The relative humidity Rh at the first end of the measuring channel 2, and thus in the structure 1, 1 i 30 surrounding it, is given by: 7 108891 (7, S «r2 ___ 7, i« T | \

Rh) = Rh2 * loh + vw'Kmjrc} '(1)

If a pulse-heated temperature sensor 9 is used, it can also be checked, if desired, for liquid water at the first end of the measuring channel 2. This is done, for example, by applying power to the temperature sensor 9 and measuring the temperature of the sensor 9 as a function of time. From the temperature change of the temperature sensor 9 per unit of energy supplied, it can be deduced whether the sensor 9 is in the air or in water. If the temperature change is substantially smaller than that of the sensor 9 disposed freely in the air, it is interpreted that liquid water is present at the first end of the measuring channel 2.

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Claims (13)

Method for forming a measuring joint in a structure (1) for measuring the moisture in the inner part of the structure (1), in which method the measuring joint is formed S while the structure (1) is formed, characterized in that a tubular angular conductor (2) is formed. ) having a first and a second end as well as a substantially moored surface in the area so limited by the ends of the meadow conductor (2), harnesses into the inner part of the structure (1) and the other end extend in contact with the surface of the structure (1) or a rupture made in the surface, such as a measuring box (3), - one end of the angel conductor (2) is substantially sealed Method according to claim 1, characterized in that ''; The angel conductor (2) is formed by bending a plastic tube to a suitable shape and. - the other end of the angel conductor (2) is closed by providing in it a * *: substantially moored meadow plug (10). * * * 9 * · 20 3. A method according to claim 1 or 2, characterized in that the first end of the angel conductor (2) is closed by means of a water-meadow penetrating protective plug (4). > ·: I A method for measuring the moisture in the inner part of a structure (1) via an i:. a measuring line provided from the structure (1) extending from the surface of the structure (1) to the inner part of the structure (1), in which method the relative humidity of the measurement joint, characterized by extends to the inner portion of the structure (1) and the other end of which to the surface of the structure (1) which is substantially impervious to the area between the first and second ends; 5. the air temperature at the first end of the angular conductor (2) is measured; - the air temperature at the other end of the angel conductor (2) is measured, - the relative humidity at the other end of the angel conductor (2) is measured, and - on the basis of the measured relative humidity and the temperate temperatures, the relative humidity at the first end of the angel conductor is determined. 10 5. A method according to claim 4, characterized in that the process - a first temperature detector (9) is brought to the first end of the angel conductor (2), - a moisture detector (7) is contacted with the lute which is at the other end of the angel conductor (2). 7) be brought into contact with the lute that is at the other end of the angel conductor (2); - the other end of the angel conductor (2) is closed substantially substantially tightly, • · t: '1 - one waits until the humidity profile of the air in the angel conductor (2) has been sufficiently smoothed out, and the first (9) and the second (7) temperature detectors as well as the moisture detector (7) measure the relative humidity of the angular conductor (2) j · ·: second end and the temperatures at the first and second ends. · * · »· 1. 6. Measurement stage for use in measuring the moisture in a structure (1) • 1 · 1 inner part, comprising * · a first end extending to the inner part of the structure (1), - a second end extending - a uniform space joining the first end to the second end, characterized in that it comprises a tubular angular conductor (2) arranged to substantially narrowly tighten the area between the first end and the second end. uniform space, which joins the first end with the second end. Measurement line according to claim 6, characterized in that it comprises a water-meadow penetrating protective plug (4), which can be arranged at the first end of the angular conductor (2). Measurement path according to claim 6 or 7, characterized in that it comprises a substantially non-water-meadow meadow plug (10) which can be arranged at the other end of the meadow (2), to prevent moisture exchange between the area surrounded by the meadow ( 2) and its other end. * »· T I I ♦ · · •. Measurement path according to any of claims 6-8, characterized in that it comprises a measuring box (3) which can be arranged at the other end of the angular conductor (2). V;: 20 »I I 10. A measuring device for measuring the moisture in the inner part of a structure (1) via an angel conductor (2) arranged in the structure (1), characterized in that it comprises: - a measuring unit (5; 5 ') for controlling the measurement and for having control over the measurement results, - a first end of the flexible conductor (5; 5 ') connected to the measuring unit (8), a temperature detector (9) connected to the flexible conductor (8) one end for measuring the temperature that rises in the first end of the angular conductor (2), - a humidity detector (7) connected to the measuring unit for measuring the humidity that rises in the other end of the angular conductor (2), a first temperature detector (7) for measuring the temperature rising at the other end of the angel conductor (2) and - a meadow stopper (6) for closing the second end of the angel conductor (2) substantially moored. 10 Measuring device according to claim 10, characterized in that - the second temperature detector (9) comprises a resistor and - the measuring unit (5; 5 ') comprises means for input of power into the temperature detector (9) resistor, wherein the the temperature of the second temperature detector (9) can be optionally raised and measured; to observe liquid water, possibly surrounding the temperature detector (9). Measurement device according to claim 10 or 11, characterized in that the first temperature detector (7) is mechanically connected to the moisture detector (7). 13. Measuring device according to any of claims 10 - 12 for use in connection with an angel conductor (2), at the other end of which a measuring box (3) is connected, characterized in -. The fact that the measuring device comprises a housing which can be arranged into the measuring box (3) and which adheres to the shape of the inner surface of the measuring box (3). I * * * *