JPH05281367A - Weather forecasting meter - Google Patents

Abstract

PURPOSE:To improve the weather forecasting accuracy of the title meter which predicts the weather by detecting a change in atmospheric pressure by eliminating the trouble caused by the conventional mechanical pressure sensor so as to improve the reliability and correcting the influence of a height difference on the atmospheric pressure. CONSTITUTION:The title meter is provided with an electronic pressure sensor 11 which detects the atmospheric pressure, difference detecting section 12 which calculates the atmospheric pressure difference between two atmospheric pressure values detects at a prescribed time interval by comparing the values with each other, and a comparing and arithmetic section 13 which discriminates a change in atmospheric pressure by comparing the atmospheric pressure difference calculated by the section 12 with a set value and specifies the trend of the weather from the discriminated result. In addition, an atmospheric pressure correcting means which compares the variation of the atmospheric pressure per unit time with the set value and, when the variation exceeds the set value, adds the correcting value corresponding to the variation to a detected atmospheric pressure value is provided in such a weather forecasting meter that forecasts the weather based on the variation of atmospheric pressure per unit time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather forecast device which detects changes in atmospheric pressure and predicts weather.

[0002]

2. Description of the Related Art Conventionally, a method of reading changes in atmospheric pressure has been widely used for forecasting weather. This method determines that the weather recovers when the atmospheric pressure rises and deteriorates when the atmospheric pressure decreases, and a mechanical pressure sensor is used as a means for reading changes in the atmospheric pressure. FIG. 11A is a plan view showing the appearance of a conventional weather forecaster using a mechanical pressure sensor, FIG. 11B is a side view thereof, and FIG. 11C is a sectional view taken along line AA of FIG. It is a figure.

In the figure, a container 1 is an atmospheric pressure detector which expands or contracts in response to a change in atmospheric pressure, and a shaft 2 at a central portion moves up and down in accordance with expansion / contraction. Changes due to expansion or contraction are caused by the U-shaped spring plate 3 from the shaft 2,
And transmitted to the push plate 5 by the arm 4 attached to one end of the spring plate 3. The push plate 5 is attached to one end of the terminal shaft 6, and the terminal shaft 6 also rotates as the push plate 5 moves up and down.
The control spring 7 gives a constant braking force to the rotation of the terminal shaft 6, and is adjusted so that the terminal shaft 6 always returns to a predetermined position. The terminal 8 is mounted so as to sandwich the terminal shaft 6, and is stopped by a weak frictional force. As a result, the terminal 8 moves up and down according to the rotation of the terminal shaft 6, and when it comes into contact with the upper terminal 9 or the lower terminal 10, the terminal shaft 6 slips and stops. Therefore, the fluctuation of the terminal 8 due to the change in atmospheric pressure, which will be described later, is peak-held. FIG. 12 (a)-
11C is an enlarged view of the AA cross section of FIG. 11C, showing three states depending on atmospheric pressure. In a state where the atmospheric pressure is low (hereinafter, state A), as shown in FIG.
The container 1 expands so that the terminals 8 and the upper terminals 9 are electrically connected. In a state where the atmospheric pressure is high (hereinafter, state C), the container 1 contracts and the terminals 8 and the lower terminals 10 are electrically connected, as shown in FIG. Further, in the state in which the state A is changed to the state C or the state C is changed to the state A (hereinafter, state B), the terminal 8 is not conducted to either side terminal as shown in FIG.

The weather forecast is judged by detecting the electrical connection between the terminals, and is displayed via an appropriate display means.
For example, it is displayed such as "recovery of weather", "worse of weather", "change of weather".

[0005]

However, as is clear from FIGS. 11 and 12, the mechanical pressure sensor used in the conventional weather forecasting device has a complicated mechanism and is costly. It was prone to failure and had low reliability. In addition, there are many problems such as errors easily occurring due to changes in the ambient temperature, product variations, and the need for 100% adjustment.

On the other hand, even at the same point where the atmospheric pressure arrangement does not change at all, the atmospheric pressure changes if the altitude changes. FIG. 13 shows how the atmospheric pressure changes due to the difference in altitude.
Since the change in atmospheric pressure (hereinafter referred to as sea level pressure) at a fixed point (0 m above sea level) is within the range of approximately 990 mb to 1030 mb, it is generally 5 mb at sea level pressure.
We make forecasts by catching changes in the degree. However, the altitude difference (about 50 m) that causes the above-mentioned change of 5 mb is
It is a height that can be easily moved in about 30 minutes for hang gliding, hiking, mountain climbing, etc. In this way, a weather forecaster that makes a weather forecast based on the rate of change in atmospheric pressure per unit time will be affected by atmospheric pressure when the altitude of the observer changes rapidly, and the weather forecast will be accurate. There was a problem that it could not be done.

It is an object of the present invention to provide a weather forecasting device which eliminates the problems caused by the conventional mechanical pressure sensor and improves reliability.

Also, the effect of atmospheric pressure due to the altitude difference is corrected,
It is an object to provide a weather forecast device that enables more accurate weather forecast.

[0009]

In order to solve the above-mentioned problems, in a weather forecaster according to the first invention, an electronic pressure sensor such as a semiconductor pressure sensor for detecting atmospheric pressure and a predetermined pressure sensor are used. A difference detection unit that compares two atmospheric pressure values detected at time intervals and calculates the atmospheric pressure difference is compared with the atmospheric pressure difference calculated by the difference detection unit and the set value, and the atmospheric pressure difference is the set value. It is characterized by comprising a comparison calculation means for judging whether the atmospheric pressure is rising or falling depending on whether it is larger or smaller, and predicting the weather condition based on the judgment result of the comparison calculation means.

A weather forecaster according to a second aspect of the present invention is a weather forecaster that makes a weather forecast based on a rate of change in atmospheric pressure per unit time, and compares the rate of change in atmospheric pressure with a set value. The change in the atmospheric pressure is determined, and when the atmospheric pressure change rate exceeds a predetermined ratio, an atmospheric pressure correction means is provided for adding a correction value corresponding to the change in atmospheric pressure to the detected atmospheric pressure value.

[0011]

In the weather forecast device according to the first invention described above,
By using an electronic pressure sensor that can read changes in atmospheric pressure as a continuous analog quantity, and performing a weather forecast by comparing and calculating two atmospheric pressure values detected by this electronic pressure sensor, The problems of the structure and performance of the conventional mechanical pressure sensor are solved.

Further, the weather forecaster according to the second invention is
When the forecast is made based on the atmospheric pressure change rate per unit time, the altitude is corrected. That is, it generally takes 3 hours for the atmospheric pressure change in the sea surface pressure to change by 5 mb even when the largest typhoon passes. This weather forecaster focuses on the fact that the atmospheric pressure change is very gradual, and it judges that a rapid change in the atmospheric pressure change rate is due to altitude and adds a correction value to the detected atmospheric pressure value, I try to make accurate weather forecasts.

[0013]

Embodiments (1) and (2) of a weather forecast device according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment (1) FIG. 1 is a block diagram showing the construction of an embodiment of the weather forecast device according to the first invention. This weather forecaster includes a pressure sensor 11, a difference detection unit 12, a comparison calculation unit 13, and a display unit 1.
4 and memories 15 to 17.

The pressure sensor 11 is an electronic pressure sensor for detecting atmospheric pressure, which reads a change in atmospheric pressure as a continuous analog amount, converts the atmospheric pressure value into a voltage value, and outputs it. Barometric pressure values are sampled at regular time intervals. As the electronic pressure sensor, for example, a semiconductor pressure sensor can be used.

The difference detector 12 compares and calculates two atmospheric pressure values sampled by the pressure sensor 11 to calculate the atmospheric pressure difference ΔP. The initially input atmospheric pressure value and the atmospheric pressure value when the equations (1) and (2) described below are satisfied in the comparison calculation unit 13 are peak-held in the memory 15 and are compared with the newly detected atmospheric pressure value in the next sampling. Be compared. The atmospheric pressure difference ΔP is calculated by Px−M, where M is the atmospheric pressure value at which the peak is held and Px is the newly detected atmospheric pressure value.

The comparison calculation unit 13 compares the atmospheric pressure difference ΔP calculated by the difference detection unit 12 with a set value, and judges the atmospheric pressure change depending on whether the atmospheric pressure difference ΔP is larger or smaller than the set value. The tendency of the weather is specified by the judgment result. The change in atmospheric pressure is determined by sequentially applying the following equations (1) to (3). It should be noted that the memory 16 in FIG.
The set value corresponding to mb is stored, and -7 is stored in the memory 17.
A set value corresponding to mb is stored. The set value is represented by a voltage value corresponding to mb.

Atmospheric pressure difference ΔP> 7 mb equivalent value (1) Atmospheric pressure difference ΔP <−7 mb equivalent value (2) Atmospheric pressure difference ΔP> 0 mb equivalent value (3) In the comparison calculation unit 13, the atmospheric pressure difference ΔP is calculated by the above formula. (1) ~
By referring to the result when applied to (3) and the counter value described later, four kinds of weather trends of “sunny”, “recovery”, “worse”, and “rain” are specified.

The difference calculation section 12 is provided in the comparison calculation section 13.
Is provided with a counter (not shown) for counting the number of peak hold times, and when the equation (1) or the equation (2) is established and the atmospheric pressure value Px is peak-held, the counter value is incremented by one. Increment. On the other hand,
When the formula (1) or the formula (2) is not established and the formula (3) is established or not established, the value of the counter does not change. In this case, the memory 15 retains the previous peak-held value as it is.

When the above equation (1) is satisfied and the counter value is 2, the comparison operation unit 13 determines that the weather is "clear".
When the expression (1) is satisfied and the value of the counter is 1, it is determined as “recovery”. When the above equation (2) is satisfied and the counter value is 2, it is determined to be "rain", and the equation (2)
When is satisfied and the value of the counter is 1, it is judged as “deteriorated”. Furthermore, when formula (3) is established, "recovery"
If it does not hold, it is judged as “worse”. When "clear" or "rainy" is displayed on the display unit 14, the counter value is reset to 0, and the other counter displays the counter value unchanged.

That is, when the formula (1) or the formula (2) is satisfied twice (or twice discontinuously) by the rise or fall of the atmospheric pressure, "clear" or "rain" is displayed and the formula ( 3)
When is satisfied, or when the formula (1) or the formula (2) is satisfied only once, “recovery” or “deterioration” is displayed.

The difference detector 12 and the comparison calculator 13 are
It can be realized by hardware and software whose main constituent elements are a CPU (central processing unit), a main storage device and the like.

The display unit 14 is a device for displaying "clear", "recovery", "worse", "rain", etc. according to the judgment result of the comparison calculation unit 13. As a display method, for example, characters may be displayed on a liquid crystal panel or the like, or characters or areas on the scale plate may be indicated by arrows, or a lamp may be turned on to notify.

Next, a processing procedure for making a weather forecast by the above-mentioned weather forecast device will be described with reference to the flowchart of FIG.

When the atmospheric pressure value Px is detected by the pressure sensor 11 (step 101), the difference detector 12 stores the value in the memory 15 as M (peak hold value) ← Px (step 102). The comparison operation unit 13 resets the counter to i ← 0 (step 103). Next, when a certain time has passed since the atmospheric pressure detection in step 101 (step 104) and the next atmospheric pressure value Px is detected by the pressure sensor 11 (step 105), the difference detection unit 12 causes the peak detector stored in the memory 15 to operate. − The value of P and the P detected this time
The atmospheric pressure difference ΔP (Px−M) is calculated from x, and the comparison calculation unit 1
Output to 3. Based on the atmospheric pressure difference ΔP output from the difference detection unit 12, the comparison calculation unit 13 determines the atmospheric pressure difference ΔP> 7 mb.
It is determined whether or not the equivalent value holds (step 10).
6). If the equation is satisfied, the pressure value Px detected this time is newly set to M (step 107), and the counter value i
Is incremented by 1 (step 108). next,
The comparison calculation unit 13 checks the counter value and determines whether i = 2 (step 109). When i = 2, it is determined to be "clear" and this is output to the display unit 14. The display unit 14 displays "clear" according to the determination result of the comparison calculation unit 13 (step 110). When "clear" is displayed, the process returns to step 103 and waits until the next atmospheric pressure detection.

Now, in step 106, ΔP> 7 m
If b is not established, it is determined whether or not the atmospheric pressure difference ΔP <−7 mb equivalent value is established (step 111). If the equation is satisfied, the pressure value Px detected this time is newly set to M (step 112), and the value of the counter is incremented by 1 (step 113). Next, the comparison calculation unit 13 checks the counter value and determines whether i = 2 (step 114). "i" when i = 2
And outputs this to the display unit 14. The display unit 14 displays "rain" according to the determination result of the comparison calculation unit 13 (step 115). When "rain" is displayed, the process returns to step 103 and waits until the next atmospheric pressure detection.

Further, in step 111, ΔP <−
When 7 mb is not established, it is determined whether or not the atmospheric pressure difference ΔP> 0 mb equivalent value is established (step 116). Here, when the formula is satisfied, and in step 109, i
When it is not = 2, it is judged as "recovery" and this is displayed
Output to. The display unit 14 displays "recovery" according to the judgment result of the comparison calculation unit 13 (step 117). On the other hand, when ΔP> 0mb is not satisfied in step 116 and when i = 2 is not satisfied in step 114, it is determined as “deteriorated” and is output to the display unit 14. In the display unit 14, “deteriorated” according to the judgment result of the comparison calculation unit 13.
Is displayed (step 118). When "recovery" and "deterioration" are displayed, the process returns to step 104 and waits until the next atmospheric pressure detection.

Next, a specific example of the weather forecast based on the above processing will be described. FIG. 3 is a graph showing an example of changes in atmospheric pressure with respect to changes in altitude. The vertical axis represents atmospheric pressure (mb) and the horizontal axis represents time. In the figure, it is assumed that the times t1, t2, ... T8 are set by a predetermined sampling interval, and the atmospheric pressure values detected at the respective times are Vt1, Vt2 ,.
Let t8.

First, at time t1, Vt1 (1020
mb) is peak-held and Vt2 (1010 mb) is subsequently detected at time t2, the atmospheric pressure difference ΔP changes from Vt2-Vt1 to -10, and the equation (2) is established.
Here, the value of Vt2 (1010 mb) is peak-held. Further, since the counter value is i = 1, the display is “deteriorated”. Next, at time t3, Vt3 (10
14 mb) is detected, the pressure difference ΔP becomes Vt3-Vt.
From 2 to 4, the equation (3) is established. Here, Vt2
The value of (1010 mb) is peak-held as it is,
The display is "Recovery". Next, at time t4, Vt4
When (997 mb) is detected, the atmospheric pressure difference ΔP becomes Vt4−
From Vt2 to −13, the equation (2) is established. Here, the value of Vt4 (997 mb) is peak-held and the counter value i is incremented by one. This gives i =
Since it becomes 2, the display becomes "rain" and the counter value is reset to 0. Next, at time t5, Vt5 (993
mb) is detected, the atmospheric pressure difference ΔP changes from Vt5-Vt4 to -4, which is not satisfied in the equation (3). Here, the value of Vt4 (997 mb) is peak-held as it is. Further, since the counter value is i = 1, the display is “deteriorated”. Here, it shows that it has worsened from the previous "rain." Next, when Vt6 (1004 mb) is detected at time t6, the atmospheric pressure difference ΔP changes from Vt6-Vt4 to 7, and the equation (3) is established. Here, the value of Vt4 (997 mb) is peak-held as it is, and the display becomes "recovery". Next, when Vt7 (1001 mb) is detected at time t7, the pressure difference ΔP
Becomes 4 from Vt7-Vt4, and the equation (3) is established. Here, the value of Vt4 (997 mb) is peak-held as it is, and the display continues to be "recovery". Note that t6
From t to t7, the atmospheric pressure temporarily drops, but t5
Looking at the change in atmospheric pressure from, it can be judged that there is a general tendency for recovery. Subsequently, when Vt8 (1012 mb) is detected at time t8, the pressure difference Δ
P becomes 15 from Vt8-Vt4, and Formula (1) is materialized. Here, the value of Vt8 (1012 mb) is peak-held and the counter value i is incremented by one.
As a result, since i = 1, the display remains "recovery" and the counter value is reset to 0. Time t mentioned above
The relationship between the atmospheric pressure difference from 2 to t8 and the display and peak hold value is shown in FIG.

Embodiment (2) FIG. 5 is a block diagram showing the structure of an embodiment of the weather forecast device according to the second invention. This weather forecaster includes a pressure sensor 21, a change rate calculation unit 22, a comparison calculation unit 23, and a display unit 2.
4 and memories 25 to 27.

The change rate calculating unit 22 calculates the rate of change in atmospheric pressure per unit time dp / dt based on the two atmospheric pressure values sampled by the pressure sensor 21 at regular time intervals. That is, the atmospheric pressure value detected last time is temporarily stored in the memory 25, and is calculated together with the new atmospheric pressure value detected after a fixed time to calculate the atmospheric pressure change rate. Then, every time the atmospheric pressure change rate is calculated at a constant time interval, the most recently detected atmospheric pressure value is stored in the memory 25. The change rate calculation unit 22
Includes a time measuring means (not shown) for measuring a predetermined time. This time measuring means may be provided in the pressure sensor 21. In this example, the atmospheric pressure change rate per hour is obtained by detecting the atmospheric pressure value detected every hour.

The comparison calculation unit 23 includes the change rate calculation unit 22.
The atmospheric pressure change rate dp / dt calculated by is compared with the set value, the atmospheric pressure change is judged depending on whether the atmospheric pressure change rate is larger or smaller than the set value, and the tendency of the weather is specified by the judgment result. The change in atmospheric pressure is expressed by the following equation (4)
Expression (7) is applied in order to make a determination. The memory 26 of FIG. 5 stores set values corresponding to the following αf, and the memory 27 stores set values corresponding to the following αR.

Dp / dt> αf (4) dp / dt <−αR (5) 0 ≦ dp / dt ≦ αf (6) −αR <dp / dt <0 (7) Here, the set value αf is appropriately selected from the values 0 <αf, and −αR is appropriately selected from the values 0> αR. That is, the comparison calculation unit 23 determines that it is sunny when the atmospheric pressure change rate dp / dt is larger than the set value αf as in the equation (4), and it is rainy when it is smaller than the set value −αR as in the equation (5). to decide. Further, when dp / dt satisfies the condition of the expression (6), it is judged to be recovered (clear and sometimes cloudy),
When dp / dt satisfies the condition of Expression (7), it is determined that the condition is worse (cloudy). Figure 6 shows the relationship between atmospheric pressure changes and forecasts. Thus, the atmospheric pressure change rate dp / dt is calculated by the above equation (4).
By referring to the results when applied to (7), four kinds of weather trends of "sunny", "recovery", "worse", and "rain" are specified.

Further, the comparison calculation unit 23 determines that the atmospheric pressure change rate dp
/ Dt is compared with a set value for atmospheric pressure correction, and when the atmospheric pressure change rate exceeds the set value, an atmospheric pressure correction means (not shown) is added to the detected atmospheric pressure value to add a correction value corresponding to the change in atmospheric pressure. I am. In this atmospheric pressure correction means, the atmospheric pressure change rate dp / dt is compared with the set value by the following equation (8) or (9), and when it is determined that the observed atmospheric pressure P has changed suddenly,
The observed atmospheric pressure P is corrected by adding a predetermined correction value (change amount) to the atmospheric pressure value. Note that the atmospheric pressure correction means may be provided in the change rate calculation unit 22.

(1) At altitude increase dp / dt <-k (8) where dp / dt is the rate of change of atmospheric pressure per 1 h (hour), and K is a set value (5 mb / h). . This set value is a specific example obtained from the atmospheric pressure change due to the altitude difference in FIG. 12 and the above-described atmospheric pressure change in the natural world.

For example, when the altitude changes at a rate of -7 mb per hour, the rate of change of atmospheric pressure at that time exceeds the set value of equation (8). That is, when the above equation (8) is established, it is determined that there is a rapid increase in altitude, and as shown below, the change ΔPa of the rapid increase in atmospheric pressure is added to P to obtain the corrected atmospheric pressure value P ′. To calculate.

P '= P + ΔPa (2) At altitude descent dp / dt> k ... (9) (dp / dt and K are the same as in the case of formula (8)) For example, the altitude changes at a rate of +7 mb per hour. In that case, the rate of change in atmospheric pressure at that time exceeds the set value of equation (9). That is, when the above equation (9) is satisfied, it is determined that there is a rapid altitude drop, and as shown below, the change -ΔPb of the sudden pressure drop is added to P + ΔPa,
The corrected atmospheric pressure value P'is calculated.

P ′ = P + ΔPa−ΔPb Thus, by adding the correction value to the observed atmospheric pressure P, the atmospheric pressure value which is the same as the sea level atmospheric pressure can always be obtained without being affected by the atmospheric pressure change due to the rapid rise and fall of the altitude. it can. In addition, when the atmospheric pressure value is corrected as described above, it is necessary to newly calculate the atmospheric pressure change rate dp / dt based on the corrected atmospheric pressure value P ′.
2 or the comparison calculation unit 23. Comparison operation unit 23
Determines the change in atmospheric pressure by applying the above equations (4) to (7) to the newly calculated rate of change in atmospheric pressure dp / dt.

The change rate calculation section 22 and the comparison calculation section 23
Can be realized by hardware and software whose main components are a CPU (central processing unit), a main storage device, and the like. In addition, the pressure sensor 21 and the display unit 24
Is the same as the embodiment (1) of FIG. 1 described above,
The description is omitted here.

Next, a processing procedure for making a weather forecast by the above-mentioned weather forecast device will be described with reference to the flowcharts of FIGS. 7 and 8.

In FIG. 7, when the pressure sensor 21 detects the atmospheric pressure value Px1 (step 201), the change rate calculating section 22 stores the value in the memory 25 (step 2).
02). The rate-of-change calculating unit 22 times out the time measurement of the time measuring means (not shown) (step 203), and the pressure sensor 21
When the atmospheric pressure value Px2 is detected by (step 20
4) Calculate an atmospheric pressure change rate dp / dt per unit time based on the atmospheric pressure values Px1 and Px2 (step 2).
05).

Next, the comparison calculation unit 23 calls the subroutine of FIG. 8 to perform the correction process of the atmospheric pressure change rate dp / dt (step 206). First, for dp / dt calculated in step 205, it is determined whether dp / dt <-k is satisfied (step 301). Here, when the expression is satisfied, it is determined that the altitude is rapidly increasing, and the correction pressure value P ′ is calculated by adding the change amount ΔPa of the pressure increase to the observed pressure P (step 302). Then, this corrected atmospheric pressure value P ′
Then, the atmospheric pressure change rate dp / dt is newly calculated (step 303), and the process returns to the main routine. When dp / dt <-k is not established in step 301, it is determined whether dp / dt> k is established (step 304). Here, when the equation is satisfied, it is determined that the altitude is rapidly decreasing, and the change in atmospheric pressure decrease -ΔPb is added to the observed atmospheric pressure P + ΔPa to calculate the corrected atmospheric pressure value P '(step 305). Then, the atmospheric pressure change rate dp / dt is newly calculated based on the corrected atmospheric pressure value P '(step 303), and the process returns to the main routine. further,
When dp / dt> k is not established in step 304,
It returns to the main routine as it is. in this case,
Atmospheric pressure change is determined based on the atmospheric pressure change rate dp / dt obtained at step 205.

After the subroutine is completed, the comparison operation unit 23 determines whether dp / dt> αf is satisfied (step 207). Here, when the expression is satisfied, it is determined that the weather is “clear”, and this is output to the display unit 24. The display unit 24 displays "clear" according to the judgment result of the comparison calculation unit 23 (step 208). Step 207
If dp / dt> αf does not hold, then dp / dt <
It is determined whether −αR holds (step 20).
9). Here, when the formula is satisfied, it is determined to be "rain", and this is output to the display unit 24. The display unit 24 displays "rain" according to the judgment result of the comparison calculation unit 23 (step 210). In step 209, dp / dt <-αR
If is not established, it is determined whether dp / dt> 0 is established (step 211). Here, when the formula is satisfied, it is determined as “recovery” and is output to the display unit 24. The display unit 24 displays "recovery" according to the judgment result of the comparison calculation unit 23 (step 212). Furthermore, when dp / dt> 0 is not established in step 211, it is determined as “deteriorated” and is output to the display unit 24. Display unit 2
In 4, the display of "deteriorated" is performed according to the judgment result of the comparison operation part 23 (step 213).

FIG. 9 shows an example of changes in atmospheric pressure due to changes in altitude. In the figure, when the observer's altitude changes like H over time, the sea level pressure becomes P0.
, The actual observed atmospheric pressure is affected by the change in the observer's altitude like P. However, by performing the above-described altitude correction, it is possible to eliminate the influence of a sudden change in atmospheric pressure. FIG. 10 shows an example in which the altitude is corrected for the observed atmospheric pressure shown in FIG. In the figure, when the altitude of the observer rises, a correction value of ΔPa is added to the observation pressure P, and when the altitude of the observer decreases, a correction value of −ΔPb is added to the observation pressure P + ΔPa. As a result, the corrected pressure P
As shown by ', it is possible to always obtain the same atmospheric pressure value as the sea level pressure P0.

In this way, when the observed atmospheric pressure changes abruptly, the correction value is added according to the condition, so that even if the altitude changes abruptly, it is not affected. Therefore, it is possible to accurately predict the weather even when carried in a sport such as a hang glider or a mountain climbing which causes an altitude difference of 50 m in about 30 minutes.

[0046]

As described above, in the weather forecast device according to the first aspect of the invention, the atmospheric pressure is detected by the electronic pressure sensor, and the pressure sensor detects the atmospheric pressure at a predetermined time interval. In addition to calculating the atmospheric pressure difference between two atmospheric pressure values, the calculated atmospheric pressure difference is compared with the set value to determine the atmospheric pressure change, and the tendency of the weather is identified based on the determination result. In addition to downsizing the device as compared to a weather forecast device using a sensor, the mechanism is simple and the cost is low, and the reliability of the device can be improved. In addition, errors due to temperature are less likely to occur, and variations in products are reduced, so that assembly adjustment and the like are unnecessary.

In the weather forecaster according to the second aspect of the present invention, the rate of change in atmospheric pressure per unit time is compared with the set value, and when the rate of change in atmospheric pressure exceeds the set value, the detected atmospheric pressure value is Since a correction value corresponding to the change is added, it will not be affected even if the observer's altitude changes suddenly, and sports such as hang gliding and mountain climbing will cause a sudden difference in altitude. More accurate weather forecasts can be made even when carried on the phone.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of a weather forecast device according to the first invention.

FIG. 2 is a flowchart showing a processing procedure when a weather forecast is made by the weather forecast device of FIG.

FIG. 3 is a diagram showing an example of changes in atmospheric pressure with respect to changes in altitude.

FIG. 4 is a diagram showing the relationship between the atmospheric pressure difference and the display and peak hold value at each time in FIG.

FIG. 5 is a configuration block diagram showing an embodiment of a weather forecast device according to the second invention.

FIG. 6 is a diagram showing the relationship between changes in atmospheric pressure and forecasts.

7 is a flowchart showing a processing procedure when a weather forecast is made by the weather forecast device of FIG.

FIG. 8 is a flowchart showing a processing procedure for performing altitude correction.

FIG. 9 is a diagram showing an example of changes in atmospheric pressure due to changes in altitude.

FIG. 10 is a diagram showing an example in which altitude correction is performed on the observed atmospheric pressure in FIG. 9;

11 (a) is a plan view showing the appearance of a conventional weather forecast device using a mechanical pressure sensor, FIG. 11 (b) is a side view thereof, and FIG. 11 (c) is A-A of FIG. Sectional view.

12A to 12C are enlarged views of the cross section AA of FIG. 11C.

FIG. 13 is a diagram showing how atmospheric pressure changes due to altitude difference.

[Explanation of symbols]

11, 21 ... Pressure sensor, 12 ... Difference detection unit, 13, 2
3 ... Comparison calculation part, 14, 24 ... Display part, 15-17 and 25-27 ... Memory, 22 Change rate calculation part

Claims (2)

[Claims] 1. An electronic pressure sensor for detecting atmospheric pressure,
By comparing two atmospheric pressure values detected by the pressure sensor at a predetermined time interval and comparing the atmospheric pressure difference with the differential detecting means, the atmospheric pressure difference calculated by the differential detecting means is compared with the set value. A weather forecasting device comprising: a comparison calculation means for judging a change in atmospheric pressure and specifying a weather tendency based on the judgment result. 2. A weather forecast device for performing a weather forecast based on a rate of change of atmospheric pressure per unit time, in which a change in pressure is judged by comparing the rate of change of atmospheric pressure per unit time with a set value. A weather forecast device characterized by comprising atmospheric pressure correction means for adding a correction value corresponding to the atmospheric pressure change to the detected atmospheric pressure value when the atmospheric pressure change is outside the set value range.