GB2081902A

GB2081902A - Electrical barometric pressure tendency indicating device

Info

Publication number: GB2081902A
Application number: GB8013270A
Authority: GB
Original assignee: PROBY WILLIAM HENRY
Current assignee: PROBY WILLIAM HENRY
Priority date: 1980-04-22
Filing date: 1980-04-22
Publication date: 1982-02-24
Also published as: GB2081902B

Abstract

A barometric pressure measuring device has a barometric transducer 1. An analogue to digital converter 2, under control of a clock 3, passes samples of the pressure detected by the transducer 1 to a shift register 4 at regular intervals, the shift register shifting the sampled pressure information sequentially through its registers when memorizing each new sampled pressure. A comparator 5 compares the present pressure with the pressure in one of the addresses to give a display 6 of barometric tendency, i.e. whether the pressure is rising or falling. <IMAGE>

Description

SPECIFICATION Barometric pressure measuring measure The present invention relates to a barometric pressure measuring device.

Various barometers are known for measuring ambient atmospheric pressure. In a device known as a barograph, the measured pressure is recorded on a rotating drum. This is useful in providing a permanent record of pressure variations as they occur. To a degree, a barograph may be used to forecast weather. Falling barometric pressure may indicate deterioration of weather The steeper the rate of fall, also known as barometric tendency, the more severe the weather to be expected. For instance a 6 millibar fall in three hours is recognized as a forecast of Force 6 winds, a 10 millibar fall in three hours is a forecast of Force 8 winds.

The present invention has been conceived as an improved barometric pressure measuring device.

The improved device comprises a barometric transducer, sampling means for sampling the ambient barometric pressure detected by the transducer at regular intervals, a memory for remembering the sampled pressures and a comparator for comparing present pressure with sampled previous pressures.

Conveniently the device will give an output of present barometric pressure in addition to the tendency. This may be based on the pressure remembered from any convenient period of time past. This period may be varied at will to give an indication of whether the tendency is itself changing.

The tendency will normally be shown as a figure.

Alternatively or additionally the tendency may be displayed in graphic form.

The improved device may also display the time of day, since it is convenient to incorporate a clock for controlling the sampling means to sample at the regular intervals.

To help understanding of the invention two specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings in which: Figure lisa block diagram ofthefirstembodi- ment, Figure 2 is a front view of the display panel of the first embodiment, Figure 3 is a block diagram of the second embodiment, and Figure 4 is a front view of the display panel of the second embodiment.

Referring first to Figure 1, an ambient pressure transducer 1 passes an analogue signal representative ofthe ambient pressure to an analogue to digital converter 2. A clock 3 controls the converter to pass a digital pressure signal to a shift register 4 and a comparator 5 at regular intervals. The shift register4 is also under the control of the clock 3 to shift the memorized pressures sequentially through its addresses at the beginning of each interval whereby the last address will contain the pressure memorized from a previous period equal to the length of each interval times the number of addresses. For example a three hour memory period will be given by a 12 address register shifting every 41 hour.

The comparator 5 is also under the control of the clock and compares the present pressure with the three hour pressure, from the last address in the register, to give a three hour tendency. The comparator controls a display 6 which displays the pressure and tendency constantly for the 1 hour interval until updated information is given under the control of the clock. Figure 2 shows the display to have a present pressure read-out 7 and a tendency read-out 8togetherwith atendencysign indicator 9.

Referring now to Figure 3, there is shown the block diagram of a more sophisticated device according to the invention. An ambient pressure transducer 11 feeds pressure information via an analogue/digital converter 12, a control processor 15, preferably a hard wired microprocessor, to a memory 14. A clock 13 feeds time via the processor 15 to the memory.

The processor instructs the memory to memorize the pressure measured at hour intervals for the six preceding hours. The display 16 is controlled by the processor and incorporates an ambient pressure readout 17, a tendency readout 18, a tendency display 19, and a clock readout 20. The tendency display shows as against a present pressure datum at the right hand side the pressure at six preceding hourly intervals. If the tendency is extreme, the processor may move the datum at the right hand side up or down - see dotted display line 1 9a whereas normally the datum will be half-way up the display - see display line 19b.

The tendency readout 18 will normally give the tendency over the previous three hours. However, controls 18', 18" may be used to set times between which tendency is to be displayed, e.g. for the six to three hours previously. If the controls 18', 18" are set for a period other than three hours, the tendency over the period will be shown at a three-hourly rate.

To avoid confusion, the controls 18', 18" will be automatically reset to give the normal tendency after a short interval of say five minutes.

CLAIMS (Filed on 21 April 1981) 1. A barometric pressure measuring device comprising a barometric transducer, sampling means for sampling the ambient barometric detected by the transducer at regular intervals, a memory for remembering the sampled pressures, a comparator for comparing present pressure with a sampled previous pressure and a tendency display controlled by the comparator for displaying the difference between the present pressure and the sampled previous pressure.

2. A barometric pressure measuring device as claimed in Claim 1 including a display of present barometric pressure.

3. A barometric pressure measuring device as claimed in Claim 1 or Claim 2 wherein the sampled previous pressure may be chosen from those for a variety of periods of time past.

4. A barometric pressure indicating device as claimed in Claim 3 wherein the period of time reverts to a standard period after a short interval if a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Barometric pressure measuring measure The present invention relates to a barometric pressure measuring device. Various barometers are known for measuring ambient atmospheric pressure. In a device known as a barograph, the measured pressure is recorded on a rotating drum. This is useful in providing a permanent record of pressure variations as they occur. To a degree, a barograph may be used to forecast weather. Falling barometric pressure may indicate deterioration of weather The steeper the rate of fall, also known as barometric tendency, the more severe the weather to be expected. For instance a 6 millibar fall in three hours is recognized as a forecast of Force 6 winds, a 10 millibar fall in three hours is a forecast of Force 8 winds. The present invention has been conceived as an improved barometric pressure measuring device. The improved device comprises a barometric transducer, sampling means for sampling the ambient barometric pressure detected by the transducer at regular intervals, a memory for remembering the sampled pressures and a comparator for comparing present pressure with sampled previous pressures. Conveniently the device will give an output of present barometric pressure in addition to the tendency. This may be based on the pressure remembered from any convenient period of time past. This period may be varied at will to give an indication of whether the tendency is itself changing. The tendency will normally be shown as a figure. Alternatively or additionally the tendency may be displayed in graphic form. The improved device may also display the time of day, since it is convenient to incorporate a clock for controlling the sampling means to sample at the regular intervals. To help understanding of the invention two specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings in which: Figure lisa block diagram ofthefirstembodi- ment, Figure 2 is a front view of the display panel of the first embodiment, Figure 3 is a block diagram of the second embodiment, and Figure 4 is a front view of the display panel of the second embodiment. Referring first to Figure 1, an ambient pressure transducer 1 passes an analogue signal representative ofthe ambient pressure to an analogue to digital converter 2. A clock 3 controls the converter to pass a digital pressure signal to a shift register 4 and a comparator 5 at regular intervals. The shift register4 is also under the control of the clock 3 to shift the memorized pressures sequentially through its addresses at the beginning of each interval whereby the last address will contain the pressure memorized from a previous period equal to the length of each interval times the number of addresses. For example a three hour memory period will be given by a 12 address register shifting every 41 hour. The comparator 5 is also under the control of the clock and compares the present pressure with the three hour pressure, from the last address in the register, to give a three hour tendency. The comparator controls a display 6 which displays the pressure and tendency constantly for the 1 hour interval until updated information is given under the control of the clock. Figure 2 shows the display to have a present pressure read-out 7 and a tendency read-out 8togetherwith atendencysign indicator 9. Referring now to Figure 3, there is shown the block diagram of a more sophisticated device according to the invention. An ambient pressure transducer 11 feeds pressure information via an analogue/digital converter 12, a control processor 15, preferably a hard wired microprocessor, to a memory 14. A clock 13 feeds time via the processor 15 to the memory. The processor instructs the memory to memorize the pressure measured at hour intervals for the six preceding hours. The display 16 is controlled by the processor and incorporates an ambient pressure readout 17, a tendency readout 18, a tendency display 19, and a clock readout 20. The tendency display shows as against a present pressure datum at the right hand side the pressure at six preceding hourly intervals. If the tendency is extreme, the processor may move the datum at the right hand side up or down - see dotted display line 1 9a whereas normally the datum will be half-way up the display - see display line 19b. The tendency readout 18 will normally give the tendency over the previous three hours. However, controls 18', 18" may be used to set times between which tendency is to be displayed, e.g. for the six to three hours previously. If the controls 18', 18" are set for a period other than three hours, the tendency over the period will be shown at a three-hourly rate. To avoid confusion, the controls 18', 18" will be automatically reset to give the normal tendency after a short interval of say five minutes. CLAIMS (Filed on 21 April 1981)

1. A barometric pressure measuring device comprising a barometric transducer, sampling means for sampling the ambient barometric detected by the transducer at regular intervals, a memory for remembering the sampled pressures, a comparator for comparing present pressure with a sampled previous pressure and a tendency display controlled by the comparator for displaying the difference between the present pressure and the sampled previous pressure.

4. A barometric pressure indicating device as claimed in Claim 3 wherein the period of time reverts to a standard period after a short interval if a non-standard period is chosen.

5. A barometric pressure measuring device as claimed in any preceding claim wherein the tendency display is in graphic form.

6. A barometric pressure measuring device as claimed in any preceding claim including a clock display.

7. A barometric pressure measuring device as claimed in any preceding claim wherein the memory is a shift register under the control of a clock to shift sampled pressures sequentially through its addres ses at regular intervals.

8. A barometric pressure indicating device as claimed in any one of Claims 1 to 6 wherein the comparator and the sampling means are included in a control processor which controls the memory to memorize the ambient pressure at regular intervals.

9. A barometric pressure indicating device substantially as hereinbefore described with reference to Figures 1 & 2 or 3 & 4 of the accompanying drawing.