JPH0335619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature sensing wire used to measure the average humidity of air within a large area.

Conventionally, various humidity sensing elements have been used to measure air humidity. However, these are all single-point devices, and in order to measure the average humidity of the air within a wide area, there is a problem in that many of them must be installed at various locations within the target area.

The present invention has been made to solve the above-mentioned problems and provide a humidity detection line suitable for measuring the average humidity of air in a wide area. A moisture-sensitive braided body made of multifilament yarn or spun yarn of non-hygroscopic synthetic fibers is interposed between a pair of electrode wires to form a moisture-sensitive wire, and a core that includes the moisture-sensitive wire can be freely vented. The humidity detection wire is coated with a protective braided body.

Next, the humidity sensing wire of the present invention will be explained based on the embodiment shown in FIG. Together, they form a moisture-sensitive line 3, and a protective braided body 4 is further coated on top of the moisture-sensitive line 3.

The parallel electrode wires 1, 1' may be made of any electrical conductor, but preferably have good oxidation resistance, corrosion resistance, and flexibility.

It is desirable that the humidity-sensitive braided bodies 2, 2' have electrical properties such as dielectric constant, dielectric power factor, insulation resistance, and impedance that change as linearly as possible with respect to changes in humidity in the air, and have little hysteresis. Therefore, the hygroscopic thread constituting the humidity-sensitive assembly is preferably one that easily absorbs and releases moisture.
If the measurement range is wide ranging from low humidity to high humidity, it is preferable to use synthetic fibers such as polyester, which inherently have low hygroscopicity, spun into a structure that easily absorbs moisture, such as multifilament yarn or spun yarn. The protective braided body 4 preferably has good air permeability and is made of non-hygroscopic yarn.

The above is an example in which the humidity-sensitive wire 3 is formed by combining two wire cores in a balanced type.As shown in FIG. 2, the humidity-sensitive braided body 2 is provided on the internal electrode wire 1, The present invention also includes a device in which a coaxial and ventilated external electrode wire 1' is provided on top to form a moisture sensitive wire 3.

In this case, the inner electrode wire 1 may be the same as the electrode wire in the embodiment of FIG. 1, but the outer electrode wire 1'
is formed by forming a braided body with thin metal wires, by winding perforated metal tapes vertically or overlappingly, or by winding metal tapes in gaps.

Furthermore, as shown in FIG. 3, in addition to the above-mentioned humidity-sensitive wire, there is also a temperature-measuring wire 7 made by equally twisting together two wire cores with conductors 5, 5' coated with insulators 6, 6'.
The present invention also includes those in which the core is formed by including the following.

The conductors 5, 5' may be metal wires that can be used as electrical conductors, but it is desirable that they have good flexibility and a large rate of change in conductor resistance value with temperature, that is, a large temperature coefficient.

Any flexible insulator may be used for the insulators 6 and 6', but if condensation occurs, it is possible to dry it by heating the temperature measurement wire with electricity, so it should be water resistant, Those with good heat resistance are preferred.

Before making measurements, obtain a reference curve in advance. That is, the humidity detection wire of the present invention is placed in a constant temperature and humidity chamber, and at each temperature, the capacitance between parallel electrode wires 1 and 1', dielectric power factor, insulation resistance, After measuring the impedance, etc. and converting these values per unit length of the parallel electrode wires 1 and 1', draw a diagram plotting the relative humidity (%) on the horizontal axis and the above electrical characteristic values on the vertical axis. put.

Next, the humidity detection wire of the present invention is laid at an appropriate location within the target area to be measured, and the capacitance, dielectric power factor, insulation resistance, impedance, etc. between the parallel electrode wires are measured, and the measured values are The relative humidity is calculated by converting the value per unit length of the parallel electrode wires 1 and 1' and comparing the converted value with the above reference curve.

It is clear that the relative humidity measurements obtained as described above are indicative of the average humidity within the area where the humidity sensing line is installed.

Furthermore, in the case of a device equipped with a temperature measuring wire, if the terminal end of the temperature measuring wire is short-circuited and a reference curve is obtained in advance for the reciprocating conductor resistance value seen from the starting end, as in the case of the moisture sensitive wire described above, it is possible to compare it with the standard curve. The comparison allows the average temperature within the installation area to be determined.

The relationship between relative humidity (%) and electrical characteristic values in the humidity detection line of the present invention was tested for one example, and the details and results are as follows.

<Example> A set of 30 0.18 mm annealed copper wires was used as the parallel electrode wire, and this was braided with 2 threads of 250 denier Telont (trade name of polyethylene terephthalate, a polyester fiber) with 12 strokes. Two 250-denier Tetoron threads are twisted together to form a moisture-sensitive wire.
A humidity detection line was created by covering the 24-stroke protective braid.

A comparative example was also prepared in which the moisture-sensitive braid was a 12-stroke braid with two 200 denier polyethylene monofilament yarns.

<Test method> Sample approximately 40m for the above examples and comparative examples.
The sample was collected and made into a coil with a diameter of about 30 cm, and suspended in a constant temperature and humidity tank with an internal volume of 1.8 m. The temperature in the tank was kept at 30°C and the relative humidity was gradually increased, as shown in Figure 4. By applying a 60Hz AC voltage V to a circuit in which the interelectrode impedance Zx of the humidity detection line and the reference impedance Zo are connected in series, and measuring the voltage Vo appearing at both ends of the reference impedance Zo, the following formula is obtained. The interelectrode impedance Zx of the humidity detection line was determined by

Z _x = Z _O (V/V _p -1) <Test results> The test results are as shown in Figure 5, and the comparative example is curve A.
As shown in , the impedance finally begins to decrease when the relative humidity exceeds 80%, but in the example, as shown in curve B, the impedance between the electrodes decreases linearly from the low humidity region to the high humidity region with respect to changes in relative humidity. Therefore, the accuracy of humidity measurement can be said to be extremely good.

As described above, the use of the humidity detection wire of the present invention has the effect that the average humidity in a wide area can be measured very easily and with good material thickness using a single detection wire.

In addition, if a device equipped with a temperature measurement line is used, the temperature within the area can also be measured, which is very effective for environmental control.

[Brief explanation of drawings]

1 to 3 are cross-sectional views of embodiments of the present invention. FIG. 4 is a circuit diagram for measuring interelectrode impedance of a humidity detection line. FIG. 5 is a comparison diagram of moisture sensitivity characteristics of an example of the present invention and a comparative example. 1, 1'... Electrode wire, 2... Moisture-sensitive braided body, 3...
...Moisture sensitive wire, 4...Protective braid, 5, 5'...Temperature measuring conductor, 6,6'...Insulator, 7...Temperature measuring wire.

Claims (1)

[Claims] 1. A moisture-sensitive braided body made of multifilament yarn or spun yarn of non-hygroscopic synthetic fibers is interposed between a pair of substantially parallel electrode wires to form a moisture-sensitive wire. A humidity sensing wire comprising a core containing a humidity sensing wire and covered with a breathable protective braid. 2. Claim No. 2, characterized in that the moisture-sensitive wire is formed by equally twisting together two wire cores in which a moisture-sensitive braided body made of multifilament yarn or spun yarn of non-hygroscopic synthetic fibers is provided on the electrode wire. Humidity detection line described in item 1. 3. The moisture-sensitive wire is characterized in that a moisture-sensitive braided body made of multifilament yarn or spun yarn of non-hygroscopic synthetic fiber is provided on the internal electrode wire, and a ventilated external electrode wire is provided coaxially thereon. A humidity detection line according to claim 1. 4. Claims 1, 2, or 3, characterized in that the core includes a temperature measuring wire made by equally twisting two wire cores each having a conductor coated with an insulator. Humidity detection line listed.