Module No. 5744

Barometric Pressure Measurement

You can use the Barometer Mode to take a reading of the barometric pressure at your current location, and to track reading changes and trends.

img_BARO_2023

Important!

Check the information at the link below to find out how to ensure correct readings.

Barometric Pressure Reading Precautions

Checking the Current Barometric Pressure

  1. Enter the Barometer Mode.

    2. Navigating Between Modes

    Entering the Barometer Mode starts measurement, and displays the barometric pressure at your current location and a barometric pressure graph.

    After you enter the Barometer Mode, the watch takes readings about every five seconds for three minutes. After that, a measurement is taken about every two minutes or every five seconds.
    To toggle between measurement interval settings, hold down (C) for at least two seconds.

    Changing the Measurement Interval of the Barometric Pressure Graph
    5594_101_BARO

    You can navigate between display screens by pressing (D).

    Checking Changes in Barometric Pressure Over Time
    5594_47_fl_BARO

    To retrigger measurement, press (A).

    To return to the Timekeeping Mode, hold down (E) for at least two seconds.

Note

When you enter the Barometer Mode, the second hand will indicate either timekeeping seconds, or the differential between barometer measurements (whichever was indicated the last time you were in the Barometer Mode).
You can change what information is indicated by the second hand.

Checking the Change in Barometric Pressure between Two Readings

The watch will automatically return to the Timekeeping Mode from the Barometer mode if you do not perform any operation for about one hour.

The measurement range is 260 hPa to 1,100 hPa (7.65 inHg to 32.45 inHg) (1 hPa (0.05 inHg) units). [- - -] will appear for the measured value if it is outside the allowable range.

Checking Changes in Barometric Pressure Over Time

The watch can be configured to show a graph of pressure readings taken every two hours or every two minutes.

You can display a graph of barometric pressure readings for the past 20 hours or the past 20 minutes. The square (mark_square) at the far right of the graph indicates the latest barometric pressure reading.

5594_48_BARO

Changing the Measurement Interval of the Barometric Pressure Graph

You can select a measurement interval of two hours or two minutes for the barometric pressure graph.

  1. Hold down (C) for at least two seconds to toggle between measurement interval settings.

    2. 5594_49_fl_BARO_comon

    When the measurement interval of the barometric pressure graph is two hours, measurements are taken every two minutes.

    When the measurement interval of the barometric pressure graph is two minutes, measurements are taken every five seconds.

Note

If you switch to the two-minute measurement interval graph, the watch will automatically return to the two-hour measurement interval graph after 24 hours.

Note that the graph will not be displayed immediately after it is switched to a two-minute measurement interval graph.

Predicting Upcoming Weather

A trend like this:

Means this:
dot_up_BARO

Rising barometric pressure, which indicates that upcoming weather probably will be fair.
dot_down_BARO

Falling barometric pressure, which indicates that upcoming weather probably will be bad.

Note

Large changes in barometric pressure and/or temperature can cause past data readings to be plotted outside of the visible area of the graph. Though plots are not visible, the data is still maintained in watch memory.

The barometric pressure graph is not displayed while Barometric Pressure Change Indications are displayed.

Barometric Pressure Change Indications

Checking the Change in Barometric Pressure between Two Readings

When you perform the procedure below in the Barometer Mode, the second hand will indicate the difference between the current barometric pressure measurement and the last auto measurement value (taken at two-hour or two-minute intervals).

  1. Enter the Barometer Mode.

    2. Navigating Between Modes

  2. Hold down (D) for at least two seconds. Release the button when [SET] starts to flash and then disappears from the display.

    3. This displays the current barometric pressure and enters the Barometric Pressure Offset Mode.

    5594_97_fl_BARO

  3. Press (E).

    4. This causes the display to show [HAND] arrowR [DIFF] or [SEC].

  4. Use (A) to select [DIFF].

    5. Each press of (A) cycles through the settings shown below.

    [DIFF]: Second hand indicates barometric pressure (Barometric Pressure Differential Indicator)

    [SEC]: Second hand indicates the current time seconds.

    Example: Barometric pressure differential of -3 hPa (-0.09 inHg) (two-hour measurement interval)

    5594_50_BARO

    Two-hour Measurement Interval: ±10 hPa (1 hPa units)
    Two-minute Measurement Interval: ±1 hPa (0.1 hPa units)

  5. Press (D) to exit the setting screen.

Note

If the barometric pressure differential is greater than +10 hPa (when the measurement interval is two hours) or +1 hPa (when the measurement interval is two minutes), the second hand will point to [OVER]. If it is less than -10 hPa (when the measurement interval is two hours) or -1 hPa (when the measurement interval is two minutes), the second hand will point to [UNDER].

A reading that is outside the allowable measurement range of 260 hPa to 1,100 hPa (7.65 inHg to 32.45 inHg), or any measurement error will cause the second hand to move to 9 o’clock.

Barometric Pressure Change Indications

Whenever the watch detects a significant change in air pressure readings (due to sudden ascent or descent, or to the passage of a low pressure or high pressure area), it will beep to let you know. An arrow will also flash on the display at this time if the watch is in the Barometer Mode, or if it is in the Timekeeping Mode with the barometric pressure graph displayed. The arrow that appears shows the direction of the pressure change. These alerts are called “Barometric Pressure Change Indications”.

This indication:

Means this:
dot_info_down_BARO_new

Sudden drop in pressure
dot_info_up_BARO_new

Sudden rise in pressure
dot_info_up_down_BARO_new

Sustained rise in pressure, shifting to a fall
dot_info_down_up_BARO_new

Sustained fall in pressure, shifting to a rise

Important!

To ensure correct barometric pressure change indication operation, enable it in a location where the altitude is constant (such as a lodge, camp area, or on the ocean).

A change in altitude causes a change in air pressure. Because of this, correct readings are impossible. Do not take readings while ascending or descending a mountain, etc.

  1. Enter the Barometer Mode.

    2. Navigating Between Modes

  2. Hold down (A) for at least two seconds.

    3. If this turns on barometric pressure trend information, [INFO ON] will stop flashing and then the [BARO] indicator will appear on the display.

    5594_51_fl_BARO

  3. To disable barometric pressure trend information, hold down (A) again for at least two seconds.

Note

If Barometric Pressure Change Indications are on, barometric pressure readings are taken every two minutes even while the watch is not in the Barometer Mode.

The barometric pressure change indication becomes disabled automatically 24 hours after it is enabled.

You will not be able to turn on barometric pressure trend information if the watch’s battery level is low.

Low battery power will also cause barometric pressure trend information to turn off automatically.

Calibrating Barometric Pressure Readings (Offset)

The watch’s pressure sensor is adjusted at the factory and normally does not require calibration. However, you can calibrate the displayed value if you notice major errors in readings.

Important!

The watch will not be able to produce correct barometric pressure readings if you make a mistake during the calibration procedure. Check to make sure that the value you use for calibration produces correct pressure readings.

  1. Enter the Barometer Mode.

    2. Navigating Between Modes

  2. Hold down (D) for at least two seconds. Release the button when [SET] starts to flash and then disappears from the display.

    3. This displays the current barometric pressure and enters the Barometric Pressure Offset Mode.

    5594_97_fl_BARO

  3. Use (A) and (C) to change the value.

    4. Setting range: 260 to 1,100 hPa (or 7.65 inHg to 32.45 inHg)

    Setting unit: 1 hPa (or 0.05 inHg)

    To return the barometric pressure setting to its initial factory default, press (A) and (C) at the same time.

  4. Press (D) to exit the setting screen.

Specifying the Barometric Pressure Unit

You can specify either hectopascals (hPa) or inches of mercury (inHg) as the display unit for barometric pressure values.

Important!

When Tokyo (TOKYO) is the Home City, the barometric pressure unit is fixed as hectopascals (hPa) and cannot be changed.

  1. Enter the Timekeeping Mode.

    2. Navigating Between Modes

  2. Hold down (D) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.

    3. Example: When your Home City is Los Angeles

    5594_fl_SET_HT_LOS_caps_comon

  3. Press (E) eight times.

    4. This causes [UNIT] to appear, with [hPa] or [inHg] flashing.

    5594_52_ALTI

  4. Press (A) to toggle between barometric pressure units.

    5. [hPa]: Hectopascals

    [inHg]: Inches of mercury

    5594_53_54_fl_BARO

  5. Press (D) twice to exit the setting screen.

Barometric Pressure Reading Precautions

The barometric pressure graph produced by this watch can be used to obtain an idea of upcoming weather conditions. However, this watch should not be used in place of precision instruments required for official weather prediction and reporting.

Pressure sensor readings can be affected by sudden changes in temperature. Because of this, there may be some error in the readings produced by the watch.

Back

Next