JPS5925192B2 - Snowfall measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a snow amount measuring device using a photoelectric element.

The conventional snowfall measuring method generally used involves a machine that lowers a board suspended from a wire from a fixed altitude on a pole to the snow surface, measures the descending distance, calculates the difference from the reference altitude, and calculates the snowfall amount. The distance to the snow surface is measured by emitting ultrasonic waves from a certain altitude toward the snow surface and measuring the time it takes for the reflected waves from the snow surface to return, and the snow accumulation is determined from the difference from the reference altitude. An ultrasonic measurement method to determine the amount of light, or an element that receives light when emitting light, by setting up two pillars and installing light emitting elements at regular intervals in the vertical direction on one of the pillars, and installing the same number of light receiving elements at corresponding positions on the other pillar. Various methods have been devised, such as measuring the amount of snow by counting the number of snowfalls.

As a method of utilizing ambient external light, there is also a method of measuring the amount of snow by using a sensor array or the like in which photoelectric elements arranged in a vertical row have their respective light-receiving surfaces facing outward.

In the case of fresh snow, the mechanical method cannot accurately detect the soft snow surface, and the ultrasonic method causes the reflection to spread due to variations in the apparent density of the snow, making it difficult to detect the height of the reflective surface. Due to insufficient measurements, it was not possible to accurately measure the amount of snowfall.

Furthermore, when measuring during snowfall, especially during a snowstorm, it becomes difficult to measure the amount of snowfall using any of the above methods.

The method of measuring the amount of snow with a sensor array using ambient external light, when there is no snowstorm, aims the light receiving surface in the horizontal direction as shown in Figure 2, and uses both the light reflected from the snow surface and the light transmitted through the snow. By performing measurements on fresh snow, this method has the advantage of having fewer errors than the other methods mentioned above.

However, in the case of a snowstorm, snow may adhere to the sensor surface and block light, making measurements difficult.

Furthermore, since the outside light at night is darker than during the day, there is a risk that it will be difficult to measure the amount of snowfall unless the light is received efficiently.

This invention solves the above-mentioned problem, and is designed to prevent inaccurate measurement of snowfall amount even if snow adheres to the surface of the transparent tube housing the photoelectric element or sensor due to a snowstorm and blocks external light. It is to be.

Another purpose is to enable measurements at night using only external light without increasing the number of light-receiving elements.

To explain this invention with reference to the accompanying drawings, a plurality of photoelectric elements M with light receiving surfaces m facing downward are arranged in a vertical row inside a vertical transparent tube 2 planted on the ground surface G with a constant interval between them. A reference photoelectric element R is provided at the top of the plurality of photoelectric elements M, each of the photoelectric elements is connected to a comparison circuit 4, and further connected to an indicator 8 via a counting circuit 6. It is a quantity measuring instrument.

Further, the number of the plurality of photoelectric elements M may be one each on the upper and lower sides, and an alarm device may be used as the indicator.

1 is the snow surface and H is the snow depth.

Arrow A1 indicates the optical path of light reflected from the snow surface, another arrow A2 indicates the path of light transmitted through the snow, and 7 is a DA conversion circuit.

1a shows a large curved surface formed when snow adheres to the lower part of the transparent tube 2 due to a snowstorm or the like.

FIG. 2 shows a conventional example, in which photoelectric elements M are arranged in a vertical line, and their light-receiving surfaces face the inner wall of the transparent tube 2.

The parts in the figure having the same drawing numbers as in FIG. 1 have the same names and functions.

The present invention is as described above, and the light-receiving surfaces m of the vertical rows of photoelectric elements M are arranged facing downward, and the output of the photoelectric element R located at the top thereof is used as the reference input of the comparator circuit 40. The amount of snowfall is measured by comparing the outputs of the photoelectric elements M connected to each other and determining the presence or absence of snowfall.

External light is uniformly and efficiently incident on the light-receiving surface m of each photoelectric element from all sides of the transparent tube, and even if the external light on that side is attenuated by snow adhering to one side of the transparent tube, it will not be reflected from other sides. Prevents errors in measuring the amount of snow by determining the presence or absence of snow based on incident external light.

In this invention, the photoelectric elements M are arranged in a vertical row below the reference photoelectric element R at the top, and each light-receiving surface is directed downward. Even if snow adheres to one side and blocks the light, light can still be received from the other side, eliminating any effect on snowfall measurement and preventing errors in snowfall measurement.

In addition, the snow surface reflects light well from above, and the photoelectric element with its light-receiving surface facing downward receives light from all sides, so the amount of light received is increased compared to the conventional example, and it is possible to use only external light without increasing the number of photoelectric elements. Measurements can be taken at night.

Furthermore, by using one photoelectric element each on the upper and lower sides and comparing the output of the upper photoelectric element with the output of the lower photoelectric element, it is possible to detect the presence or absence of snowfall and issue a snowfall warning.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 2...Transparent tube, M...Photoelectric element, R.
...Reference photoelectric element, m... Light receiving surface, 4
... Comparison circuit, 6 ... Counting circuit, 8.
·····display.

Claims (1)

[Claims] 1. Inside a vertical transparent tube 2 planted on the ground surface G, a plurality of photoelectric elements M with their light-receiving surfaces facing downward are arranged in a vertical row with a constant interval between them. A reference photoelectric element R is provided at the top of the plurality of rows of photoelectric elements M, and each of the photoelectric elements is connected to a comparison circuit 4 and connected to a display 8 via a counting circuit 6. A snowfall measurement device. 2. The snow amount measuring device according to claim 1, characterized in that the number of the plurality of photoelectrons M is set to - in each of the upper and lower sides, and an alarm device is used as the indicator.