JPH05323046A - Apparatus and method for measuring snowfall - Google Patents

Abstract

PURPOSE:To measure a snowfall at a high accuracy with a smaller size and a simple construction without causing drop in sensitivity and malfunction by garbage and sunlight. CONSTITUTION:A main thermistor 16 is arranged on a heat transfer plate 10 for receiving snow fall and a sub-thermistor 17 on a heat transfer plate 11 for correction receiving no snow. A controller 36 controls the supply of power with power supply circuits 31 and 32 from detection outputs of a voltage detection circuit 33 of the main thermistor and a voltage detection circuit 34 of the sub-thermistor. Electric energy supplied to the main and sub-thermistors is measured with watt-hour meters 37 and 38 to determine the intensity of snowfall from the difference between the results.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for detecting snowfall and measuring the amount of snowfall. More specifically, the present invention relates to a snowfall measuring device and method suitable for automatically operating a snowmelting device such as a water spray type, an electric heater type, a hot water pipe burying type, or the like during snowfall.

[0002]

2. Description of the Related Art As methods for detecting snowfall or measuring snowfall, there are, for example, an electrode method, a laser beam method, an ultrasonic method, a method using a thermocouple, and the like. In the electrode method, a heater is provided on the back surface of the inclined snow receiver, both electrodes are provided on the front surface at regular intervals, and when the snow on the snow receiver melts, the snow is melted by the electric conductivity between the electrodes to prevent snowfall. Detect. In the laser beam method, as shown in Japanese Patent Laid-Open No. 55-129783, a vertically movable laser light emitting source and a vertically extending light receiving column for receiving the laser beam from the light emitting source are spaced from each other. The height of the light emitting source where the light receiving column starts to receive the laser beam is measured as the snow depth. In the ultrasonic method, as disclosed in JP-A-55-9181, ultrasonic waves are radiated from the horn toward the snow surface directly below, and the ultrasonic waves reflected by the snow surface are converted by the horn into a signal and received. It is supplied to the circuit, where it processes the signal due to the reflection component and measures the amount of snowfall.

In the thermocouple method, Japanese Patent Publication No. 57-605
As shown in Japanese Patent Publication No. 85, the first and second heaters and one thermocouple are provided on the snow-receiving heating plate that receives snow, and one heater and one thermocouple are provided on the correction heating plate that does not receive snow. And the second heater of the snow-receiving heating plate and the heater of the correction heating plate are connected in series. The outside air temperature at which rain turns into snow is about 3 ℃
In the case of the following, current is passed through the two heaters connected in series, and the temperatures of the heating plate for correction and the heating plate for correction are kept constant. Here, when there is snow, the temperature of the snow-receiving heating plate decreases, so an electric current is passed through the first heater of the snow-receiving heating plate to make it equal to the temperature of the correction heating plate, and the snow-receiving heating plate is heated. Keep the plate temperature constant. It is possible to know the amount of snowfall by measuring the amount of electric power flowing through the first heater.

[0004]

In the electrode method of [Problem to be Solved by the Invention], when dust is accumulated between electrodes in the absence of snowmelt water,
Even a small amount of this dust causes conduction between the electrodes, which causes malfunction. In addition, since the electrodes come into direct contact with moisture,
Rust is likely to occur, and when the electrodes are silver, ion migration (ion migrat) occurs in the snowmelt water even if there is no snowmelt water between the electrodes.
ion) occurs and becomes conductive, causing malfunction.
In the laser beam method, if the light emitting source or the light receiving column is covered with dust or the like, the sensitivity is significantly reduced. In addition, malfunctions are likely to occur due to reception of light sources such as sunlight other than light emitting sources. The same applies to the case of the ultrasonic method, and the apparatus tends to be expensive. In any of the above cases, it works even when the temperature is high. In the thermocouple method, the number of heaters is large, the structure is complicated, and the size cannot be reduced. Further, the thermocouple has a relatively low sensitivity to temperature changes, and in order to make it highly sensitive and improve the accuracy of the thermocouple, it is necessary to improve the accuracy of the reference temperature (zero contact point), etc., and the system becomes expensive. ..

An object of the present invention is to provide a snowfall amount measuring apparatus and method capable of highly accurately measuring the snowfall amount with a small and simple structure without causing a decrease in sensitivity and malfunction due to dust or sunlight. To do.

[0006]

The structure of the present invention for achieving the above object will be described with reference to FIG. The snowfall measuring device of the present invention is a snow-receiving heat conduction plate 10 for receiving falling snow.
A correction heat conduction plate 11 that does not receive falling snow; a main thermistor 16 that is provided in contact with the snow reception heat conduction plate 10 and that can heat the snow reception heat conduction plate 10 by self-heating; The auxiliary thermistor 17, which is provided in contact with the conductive plate 11 and can heat the correction heat conductive plate 11 by self-heating, the first voltage detection circuit 33 for detecting the voltage applied to the main thermistor 16, and the auxiliary thermistor 17. The resistance value R _B of the auxiliary thermistor 17 is set based on the output of the second voltage detection circuit 34, which detects the applied voltage, and the auxiliary thermistor 17, by causing a current to flow through the auxiliary thermistor 17. Sub-thermistor power supply circuit 32 for adjusting and maintaining the second resistance value R _B3 corresponding to a predetermined outside temperature during snowfall
Then, a current is passed through the main thermistor 16 and the main thermistor 16
Power supply circuit for the main thermistor which controls the resistance value R _A of the main thermistor 16 to become the first resistance value R _A3 corresponding to a predetermined ambient temperature based on the output of the first voltage detection circuit 33 by self-heating 31 and a first watt-hour meter 37 that measures the amount of power supplied by the main thermistor power supply circuit 31.
The second watt-hour meter 38 for measuring the amount of electric power supplied by the sub-thermistor power supply circuit 32.

According to the snowfall measuring method of the present invention, first, a weak current is supplied to the sub-thermistor 17 provided in contact with the correction heat conduction plate 11 which does not receive snow, so that the thermistor 17 does not self-heat, The resistance value R _B of the sub thermistor 17 due to the weak current is measured. Here, when the outside temperature changes to about 3 ° C. or less when the rainfall changes to snow, that is, the resistance value R _B of the auxiliary thermistor 17 corresponds to this temperature, the second resistance value R _B3.
When the above is reached, a current is passed through the sub thermistor 17,
The thermistor 17 is self-heated and its resistance value R _B is adjusted and maintained so as to become the second resistance value R _B3 corresponding to the predetermined outside air temperature. Snow conduction heat conduction plate 1 for receiving the next snow
_A current is passed through the main thermistor 16 provided in contact with 0 to adjust and maintain the resistance value R _A of the main thermistor 16 to be the first resistance value R _A3 corresponding to the predetermined ambient temperature. Furthermore, after measuring the amount of electric power consumed by the main thermistor 16 and the amount of electric power consumed by the sub thermistor 17, the difference between the two amounts of electric power is obtained, and it is necessary to melt the snow received by the snow-receiving heat conductive plate 10 from this difference. The amount of heat generated is calculated, and this amount of heat is divided by the snow receiving area of the heat receiving plate for snow reception 10 to obtain the snowfall intensity.

The present invention will be described in detail below. As shown in FIG. 1, the snowfall measuring device of the present invention includes a snow-receiving heat conduction plate 10 that receives falling snow and a correction heat conduction plate 11 that does not receive falling snow. It is fixed to the end of 13 with an adhesive, a screw, or the like so as to close the insides 12a and 13a. As shown in FIG. 2, a single hollow body 1
The snow-receiving heat conduction plate 10 may be provided on the upper surface of the hollow body 4, and the correction heat conduction plate 11 may be provided on the lower surface of the hollow body 14. In this case, the size is further reduced and the mounting cost is low. By blocking the hollow body with the heat conduction plate, it is possible to prevent snow, rain, water vapor, dust, etc. from entering the hollow body interiors 12a to 14a where the thermistor is attached. The heat conductive plates 10 and 11 are silver,
A material having a large thermal conductivity, such as copper, is preferable from the viewpoint of sensitivity, and it is more preferable to perform surface treatment so as not to generate rust. Further, the correction heat conduction plate 11 is formed of the same heat dissipation constant as the snow reception heat conduction plate 10, that is, the same material with the same shape, and the correction can be easily performed in the same environment as the snow reception heat conduction plate 10. It is preferable because it simplifies the design. When the heat dissipation constants of the two heat conducting plates 10 and 11 are the same, the amount of heat generated by the thermistors 16 and 17 attached thereto must be the same, so that the main thermistor 16 and the auxiliary thermistor 17 have a predetermined temperature. First resistance value R _A3
And the second resistance value R _B3 are set to the same value. However, when the shapes and types of the two heat conduction plates 10 and 11 are different, the resistance value of the main thermistor 16 is changed to the resistance value of the sub thermistor 17 accordingly.

When the snow-receiving heat conduction plate 10 is provided with a slope as shown in FIG. 2, it is preferable that the snowmelt water flows down from the heat conduction plate 10. This is because when the snow melting water is stored on the surface of the snow receiving heat conductive plate 10 due to surface tension or the like, the heat energy consumed for melting the snow of the snow receiving heat conductive plate 10 is also spent for raising the temperature of the snow melting water, This is because the thermal energy for snow melting cannot be measured accurately. Hollow bodies 12, 13 and 14 are preferably thermal non-conductors to reduce measurement errors and not increase power consumption. This inclination angle θ is determined from the range of 10 to 40 degrees. If the angle θ is less than 10 degrees, the snowmelt water will not flow easily, while if it exceeds 40 degrees, snow will not easily adhere, which is not preferable.

A main thermistor 16 is provided on the heat conducting plate 10 for receiving snow.
However, the correction heat conduction plate 11 is provided with the auxiliary thermistors 17 in contact therewith. It is preferable that the thermistor characteristics of the sub thermistor 17, that is, the resistance value and the temperature coefficient at a predetermined ambient temperature at which rain changes into snow, are the same as the thermistor characteristics of the main thermistor 16 for easy correction. Specifically, these thermistors 16 and 17 are NT respectively.
The C thermistor is provided on each of the back surfaces of the snow-receiving heat conduction plate 10 and the correction heat conduction plate 11 when the surface is a surface in contact with the outside air as shown in the figure. When the correction heat conduction plate 11 is covered with the snowproof or rainproof cover 18 (FIG. 1),
Although not shown, the auxiliary thermistor 17 is a correction heat conduction plate 11.
It may be provided on the surface of. It is preferable to provide the cover 18 with the ventilation hole 18a because the correction accuracy is improved. Also hollow body 1
A main thermistor 16 and a sub thermistor 17 are adhered to the inner surfaces of the snow-receiving heat conduction plate 10 and the correction heat conduction plate 11 which are arranged in FIG. Hollow body 12,
13 and the cover 18 are attached to the base plate 21 by screws 19 and the hollow body 14 is attached to the inner surface of the wall 23 via the hollow arm 22. The substrate 21 and the wall 23 are installed in a snowfall place. The substrate 21 has the thermistor wiring holes 19a, 19
b, the wall 23 is provided with a thermistor wiring hole 23a. The distal end of the hollow arm 22 penetrates the hollow body 14 and is fixed to the hollow body 14, and the proximal end of the hollow arm 22 covers the wiring hole 23a and is bonded to the wall 23. When the wall 23 is a cylinder wall and the hollow body 14 is provided inside the cylinder wall, the snowfall can be stably and highly accurately measured even during snowstorm.

As shown in FIG. 1, the wiring 16a of the main thermistor 16 is connected to the power supply circuit 31 for the main thermistor through the wiring hole 19a, and the wiring 17a of the sub thermistor 17 is connected.
Is the power supply circuit 3 for the sub thermistor through the wiring hole 19b.
Connected to 2. A first voltage detection circuit 33 that detects a voltage applied to the main thermistor 16 and a second voltage detection circuit 34 that detects a voltage applied to the sub thermistor 17 are connected to the wirings 16a and 17a, respectively. Reference numeral 35 is a power supply terminal. The detection outputs of the voltage detection circuits 33 and 34 are connected to a controller 36 composed of a microcomputer. The power supply circuits 31 and 32 are connected to a first watt-hour meter 37 and a second watt-hour meter 38 that measure the amount of power supplied to the thermistors 16 and 17 by the power supply circuits 31 and 32, respectively. These electricity meters 37 and 38
Each output of is connected to the controller 36. The control output of the controller 36 is connected to the power supply circuits 31, 32, the printer 39, and the snow melting device 40. The wires 16a and 17a of the thermistors 16 and 17 shown in FIG. 2 are bundled and connected in the form of a wire harness 41 to the power supply circuits 31 and 32 outside the wall 23 through the hollow arm 22 and the wire hole 23a. In FIG. 2, other electric circuits shown in FIG. 1 are omitted.

Next, a method of using the snowfall measuring device having such a configuration will be described. <Measurement Preparation> First, a weak current that does not self-heat is supplied to the sub thermistor 17, the resistance value R _B is obtained from the voltage detected by the voltage detection circuit 34, and the outside air temperature at the measurement location is measured from this resistance value. It is empirically known that when the outside air temperature is 3 degrees Celsius or less, it will snow instead of rain.
When the outside air temperature is 3 ° C or less, the measurement is continued and the secondary thermistor 17
The main thermistor 16 is adjusted and maintained at the resistance values R _A3 and R _B3 corresponding to the predetermined temperature of 3 ° C. Specifically, the controller 36 causes the voltage supply circuits 31 and 32 to supply currents for self-heating to the main thermistor 16 and the sub thermistor 17, respectively, and the resistance values R _A and R obtained from the voltages detected by the voltage detection circuits 33 and 34. _B is R _A = R _A3
And R _B = R _B3 . Thermistor 16
And the thermistor characteristics of the thermistor 17 are the same, R
_A = R _B, and the current flowing on both thermistors 16 and 17 becomes i _A = i _B.

<Measurement of Snowfall> Snow C (Fig. 1)
When the snow receiving heat conducting plate 10 receives the snow C and the heat conducting plate 10 is cooled by the snow, the resistance value R of the thermistor 16 increases.
_A tries to be larger than R _A3 . When the resistance value R _A of the thermistor 16 starts to become larger than R _{A3, the} controller 36 increases the current i _A flowing through the thermistor 16 to heat it by itself to heat the heat conduction plate 10 and always to the thermistor 16
The resistance value R _A is maintained at R _A3 . When the current i _{A of the} thermistor 16 becomes larger than the current i _{B of the} thermistor 17, it can be detected that the snowfall state has occurred. Further, the difference in current value (i _A −i _B ) or the difference in power (P = P _A −
P _B ), the amount of electric power required to keep the thermistor 16 at the same temperature as the thermistor 17 is known, so the snowfall intensity V (g / c
m ² · min) can be obtained.

That is, the snow-conducting heat-conducting plate 10 for receiving falling snow.
Snowfall area S (cm ² ) of S
(G / min), which is melted by the heat of the thermistor 16 at 3 ° C. Therefore, if the melting heat of snow is 80 cal / g, the amount of heat is 80 · S · V (cal / min).
On the other hand, the power difference P (watt · sec) is 60 per minute.
Since it is P / 4.2 (cal / min), it becomes 60 * P / 4.2 = 80 * S * VV = P / 5.6 * S (1). The amount of electric power consumed by the main thermistor 16 and the sub thermistor 17 is measured by the watt-hour meters 37 and 38, and the controller 36 obtains the difference P, and the snow receiving area S of the snow receiving heat conductive plate 10 which is known in advance. From the above, the snowfall intensity V is obtained from the above equation (1). The snowfall intensity obtained by the controller 36 is printed on the printer 39, and when the snowfall intensity exceeds a predetermined value, the snow melting device 40 is operated.

[0015]

EXAMPLES Next, examples of the present invention will be described. The invention is not limited to this embodiment. As shown in Figure 1,
A snow-receiving heat conduction plate 10 and a correction heat conduction plate 11 made of a copper plate are attached to the upper surfaces of hollow bodies 12 and 13 made of vinyl chloride pipe by an epoxy adhesive. Hollow body 12
Outer diameter is 21mm and inner diameter is 14m.
m, height 15 mm. Further, each size of the heat conduction plates 10 and 11 has a diameter of 20 mm and a thickness of 0.3 mm. Outer diameter 2.0 mm, inner diameter 1.1 mm, length 3.8 mm
Insert the thermistor element into the glass tube and prepare two thermistors made by enclosing the thermistor element in the glass tube with the dumet wire pressed against both ends of the thermistor element. Both of these thermistors are 3 ° C
Has a resistance R ₃ of 6.0 kΩ and a B constant between 3 ° C. and 25 ° C. of 3370 K and is a DHT (double heat-sink diode thermister) type thermistor with a wire diameter of 0.3 mm. One thermistor is the main thermistor 1
6 is fixed to the back surface of the snow-receiving heat conductive plate 10 and the other thermistor is used as the sub thermistor 17 by resin molding with an epoxy adhesive on the back surface of the correction heat conductive plate 11.

Hollow body 1 having a thermistor and a heat conducting plate
Approximately 7 cm of 2 and 13 on the substrate 21 with the screw 19
Install separately. Wiring 1 of the electric circuit shown in FIG.
6a and 17a are connected to the thermistors 16 and 17, respectively. The hollow body 13 has no holes on the upper surface and a diameter of 1.
A cylindrical cover 18 having a diameter of 70 mm and a height of 70 mm in which a large number of 5 mm vent holes 18a are opened is covered, and is fixed by a screw 19 so that the hollow body 13 is located at the center thereof. I prepared for measurement without snowfall. That is, the correction heat conduction plate 11
Thermistor 17 is weak enough to prevent self-heating.
As a result of measuring the resistance value by applying a current of μA, 6.7
It was 4 kΩ and was about 0 ° C. when converted into temperature. Since the resistance value of the thermistor 14 of the correction heat conduction plate 11 was 6 kΩ or more, the current of i _B was increased to 6 kΩ, that is, 3 ° C.
I decided to keep it. The current value required for this was 1.2 mA. At this time, the current value of the thermistor 16 required to keep the snow-receiving heat conductive plate 10 at 3 ° C. was also 1.2 mA.

Next, the measurement was started. When the snow started to fall, the resistance value R _A of the snow-receiving heat conductive plate 10 started to increase from 6 kΩ, so that the current i _A was further increased and the resistance value R _A was increased.
To have a resistance value R _{A3 of} 6.0 kΩ. Since the current value i _A was larger than i _B , it was possible to detect that the snow started to fall. Subsequently, the beaker was exposed to snow for a certain period of time within which the snowfall intensity was considered to be almost constant, and the amount of snow falling on a certain area was calculated. The snowfall intensity calculated from the weight at this time was 1.6 mg / min · cm ² . On the other hand, the current flowing through the thermistor 16 of the snow receiving heat conductive plate 10 at this time is 3.3 mA on average, and the thermistor 1 of the snow receiving heat conductive plate 10 is
The average current passed through No. 7 was 1.1 mA, and the difference was 2.
It was 2 mA. At this time, the difference P in the amount of electric power between the thermistor 16 and the thermistor 17 is P = i ² · R = (2.2 × 10 ⁻³ ) ² × 6 × 10 ³ = 2.
9 × 10 ^-2 (W) and the area S is 3.14 cm ² , so the above formula (1)
As a result, V = P / 5.6 · S = 1.65 mg / min · cm ² , and it was confirmed that the values were almost the same as the values calculated from the amount collected by the beaker. Furthermore, when the snow i turns into rain, the resistance value is 6K even if the current i _B is reduced to 1 μA.
It was found that the temperature was below Ω, that is, above 3 ° C, and it was possible to distinguish between snow and rain.

[0018]

According to the present invention, the thermistor is provided in contact with the heat conducting plate, and in particular, the thermistor itself can be self-heated to maintain the snow conducting heat conducting plate at a constant temperature. The snowfall detection system becomes extremely simple. Therefore, there is no malfunction due to dust etc., it is possible to obtain a small, low-priced snow detection system, and since the thermistor itself is a temperature sensor, it is designed not to operate in high temperature conditions. It is possible to save power. In addition, by making the thermistor characteristics and resistance values of the main thermistor and auxiliary thermistor, which are provided in contact with the snow-receiving heat conduction plate that receives the falling snow and the correction heat conduction plate that does not receive the falling snow, to be the same after the snowfall. It is possible to accurately measure the increase amount of the current flowing in the thermistor. Further, since the thermistor has extremely high sensitivity to temperature changes, and the thermistor does not require a reference point (zero contact point) like a thermocouple, it is easy to achieve high accuracy.

Further, since the amount of snowfall is obtained by utilizing the heat of melting of the snowfall, a heat receiving plate for receiving snow for detecting the snowfall is set at 3 ° C.
The amount of electric power per unit area required for holding is easily known. Since this amount of electric power is the amount of electric power required at that time to melt the snow, if this is combined with the snow melting device, the snow melting device can be adjusted according to the snow accumulation state and the outside air conditions such as temperature, airflow, and humidity. Since the power of the snow melting device can be adjusted, it is possible to save the power of the snow melting device. It should be noted that the thermistor has a higher sensitivity to temperature than a thermocouple, and since the resistance value can be selected variously, the sensitivity can be easily increased. For example, even in the case of a chromel-alumel thermocouple having a relatively large electromotive force, the resistance value changes by about 4% per 1 ° C. in the thermistor, while it is 0.04 mV per 1 ° C., so that the resistance value is 5 kΩ and the current value is 1 mA, 200 mV. Even 1 μA has a very high detection sensitivity of 0.2 mV, which simplifies the detection circuit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a snowfall measuring device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a snowfall measuring device according to another embodiment of the present invention.

[Explanation of symbols]

 10 Snow-receiving heat conduction plate 11 Correction heat conduction plate 12, 13, 14 Hollow body 14a Hollow body inside 16 Main thermistor 17 Sub-thermistor 31 Main thermistor power supply circuit 32 Sub-thermistor power supply circuit 33 First voltage detection circuit 34 2nd voltage detection circuit 36 Controller 37 1st electric energy meter 38 2nd electric energy meter

Claims (8)

[Claims] 1. A heat conduction plate (10) for receiving snow, a correction heat conduction plate (11) which does not receive snow, and a heat conduction plate (10) for contacting the snow. Main thermistor capable of heating the snow-receiving heat conduction plate (10) by self-heating
(16) and an auxiliary thermistor which is provided in contact with the correction heat conduction plate (11) and can heat the correction heat conduction plate (11) by self-heating.
(17) and a first for detecting a voltage applied to the main thermistor (16)
A second voltage detecting circuit (33) for detecting a voltage applied to the auxiliary thermistor (17)
A voltage is detected in the voltage detection circuit (34) and in the sub thermistor (17).
(17) is self-heated, and the resistance value (R _B ) of the sub thermistor (17) is adjusted to a second resistance value (corresponding to a predetermined outside temperature during snowfall) based on the output of the second voltage detection circuit (34). R _B3 ), the main thermistor power supply circuit (32) for adjusting and maintaining the main thermistor (16) and the main thermistor (16).
(16) is self-heated, and the resistance value (R _A ) of the main thermistor (16) is adjusted based on the output of the first voltage detection circuit (33) to the first resistance value (R _A3 The main thermistor power supply circuit (31) that adjusts and maintains the power consumption of the main thermistor, the first watt hour meter (37) that measures the amount of power supplied by the main thermistor power supply circuit (31), and the sub thermistor. A snowfall measuring device comprising a second watt hour meter (38) for measuring the amount of electric power supplied by the electric power supply circuit (32). 2. The power supply circuits (31, 32) for the main thermistor and the auxiliary thermistor are controlled from the respective detected voltage values of the first and second voltage detection circuits (33, 34) to control the first and second power supplies, respectively. The difference between the electric energy measured by each of the electricity meters (37, 38) is calculated and the heat quantity required for melting the snow received by the snow-receiving heat conduction plate (10) is calculated from the difference. Heat conduction plate for snow (10)
Controller that outputs the snowfall intensity by dividing by the snowfall area
The snowfall measuring device according to claim 1, further comprising (36). 3. A snow-receiving heat-conducting plate (10) is provided so as to receive snow falling on its surface, and a main thermistor (16) is provided in contact with the back surface of the snow-receiving heat-conducting plate (10). The snowfall measuring device according to claim 1, wherein the auxiliary thermistor (17) is provided in contact with the front surface or the back surface of the correction heat conduction plate (11). 4. The correction heat conduction plate (11) is a snow reception heat conduction plate (1).
The snowfall measuring device according to claim 1, which has the same shape and the same material as those of 0). 5. The thermistor characteristic of the auxiliary thermistor (17) is the same as the thermistor characteristic of the main thermistor (16),
The snowfall measuring device according to claim 1, wherein the resistance value (R _A3 ) is the same as the second resistance value (R _B3 ). 6. A heat conducting plate (10) for receiving snow on the upper surface of a hollow body (14).
Is provided on the lower surface of the hollow body (14) for correction heat conduction plate (1
1) is provided, the main thermistor (16) is provided on the inner surface of the snow-receiving heat conduction plate (10) that faces the inside of the hollow body (14a), and the correction heat that faces the inside of the hollow body (14a) is provided. The snowfall measuring device according to claim 1, wherein an auxiliary thermistor (17) is provided on the inner surface of the conductive plate (11). 7. The snowfall measuring device according to claim 1 or 2, wherein the snow-receiving heat conduction plate (10) is provided with a slope. 8. A weak current is supplied to a sub-thermistor (17) provided in contact with a correction heat conduction plate (11) which does not receive falling snow so that the sub-thermistor (17) does not self-heat, Resistance value (R _B ) of the sub thermistor (17) due to current
When the rainfall reaches a predetermined outside temperature that changes to snow, a current is passed through the sub thermistor (17) to self-heat the sub thermistor (17) and the resistance value (R _B ) thereof is set to the predetermined value. Adjust and maintain the second resistance value (R _B3 ) corresponding to the outside temperature of the snow, and apply current to the main thermistor (16) provided in contact with the snow-receiving heat conduction plate (10) that receives the falling snow. Flowing and adjusting and maintaining the resistance value (R _A ) so as to become the first resistance value (R _A3 ) corresponding to the predetermined outside air temperature, measuring the amount of power consumed by the main thermistor (16), The amount of power consumed by the sub thermistor (17) is measured, the difference between the two amounts of power is obtained, and the amount of heat required to melt the snow received by the snow-receiving heat conductive plate (10) is obtained from this difference, A snowfall amount measuring method for obtaining a snowfall intensity by dividing the amount of heat by the snow-receiving area of the snow-receiving thermal conductive plate (10).