E-48
Reading the Barometric Pressure Graph
The barometric pressure graph shows a chronological history of pressure readings.
• When display of the barometric change indicator is disabled, the graph shows the results of up to 21
barometric pressure readings (42 hours).
• When display of the barometric change indicator is enabled, the graph shows the results of up to 11
barometric pressure readings (22 hours).
• The horizontal axis of the graph represents time, with each dot standing for
two hours. The rightmost dot represents the most recent reading.
• The vertical axis of the graph represents barometric pressure, with each
dot standing for the relative difference between its reading and that of the
dots next to it. Each dot represents 1 hPa.
The following shows how to interpret the data that appears on the barometric pressure graph.
Rising barometric pressure indicates that upcoming weather will improve.
Falling barometric pressure indicates that upcoming weather will deteriorate.
Note
• If there are sudden changes in weather or temperature, the graph line of past reading
may run off the top or bottom of the display.
• The following conditions cause the barometric pressure reading to be skipped, with
the corresponding point on the barometric pressure graph being left blank.
– Barometric reading that is out of range (260 hPa to 1,100 hPa or 7.65 inHg to 32.45
inHg)
– Sensor malfunction
Barometric
pressure
Time
Barometric
pressure
Time
Not visible on
the display
Not visible on
the display
E-49
Barometric Pressure Differential Pointer
This pointer indicates the relative difference between the most recent
barometric pressure reading indicated on the barometric pressure graph
(page E-48), and the current barometric pressure value displayed in the
Barometer/Thermometer Mode (page E-47).
Reading Barometric Pressure Differential Pointer
Pressure differential is indicated in the range of
±10 hPa, in 1-hPa units.
• The nearby screen shot, for example, shows
what the pointer would indicate when the
calculated pressure differential is
approximately – 0.15
inHg).
• Barometric pressure is calculated and
displayed using hPa as the standard. The
barometric pressure differential also can be
read in inHg units as shown in the illustration
(1 hPa
=
0.03 inHg).
Barometric
pressure
differential
pointer
Barometric
pressure
differential
pointer
−0.15
−5
−10
−0.3
Barometric pressure
differential pointer
inHg values
hPa values
Current pressure
greater than most
recent measured
pressure
Current pressure
less than most
recent measured
pressure
−0.15
−5
−10
−0.3
Barometric pressure
differential pointer
inHg values
hPa values
Current pressure
greater than most
recent measured
pressure
Current pressure
less than most
recent measured
pressure
E-50
Barometric Pressure Change Indications
Your watch analyzes past barometric pressure readings and uses a barometric pressure change indicator
to inform you about changes in pressure. If it determines there has been a signifi
it will beep and all of the graphic segments (
pressure change alert. This means you could start taking barometric pressure readings after reaching a
lodge or camp area, and then check the watch the next morning for changes in pressure, and plan you
day’s activities accordingly. Note that you can enable or disable display of the barometric pressure change
indicator as desired.
Reading the Barometric Pressure Change Indicator
Indicator Meaning
Sudden fall in pressure.
Sudden rise in pressure.
Sustained rise in pressure, changing to a fall.
Sustained fall in pressure, changing to a rise.
• The barometric pressure change indicator is not displayed if there has been no noteworthy change in
barometric pressure.
E-51
Important!
• To ensure proper results, take barometric readings under conditions where the altitude remains
constant.
Example
– In a lodge or campground
– On the ocean
• A change in altitude causes a change in barometric pressure. Because of this, correct readings are
impossible. Do not take readings while ascending or descending a mountain, etc.
Enabling or Disabling Display of the Barometric Pressure Change Indicator
You can enable or disable display of the barometric pressure change indicator as desired. When display
of the indicator is enabled, the watch will take a barometric pressure reading every two minutes,
regardless of the mode it is in.
• When
BARO
is shown on the display, it means that barometric pressure change indicator display is
enabled.
• When
BARO
is not on the display, it means that barometric pressure change indicator display is
disabled.
To enable or disable the barometric pressure change alert
In the Barometer/Thermometer Mode, hold down
B
for at least two seconds. Keep
B
depressed until
the current setting (
INFO Hold ON
or
INFO Hold OFF
) starts to fl
• If barometric pressure change indicator display is currently enabled,
BARO
will also appear in the
upper display.
BARO
will not appear if display is currently disabled.
• Note that barometric pressure change indicator display will turn off automatically 24 hours after you
turn it on or battery power goes low.
E-52
• Note that time calibration signal reception and power saving (page E-13) are disabled while barometric
pressure change indicator display is enabled.
• Note that barometric pressure change indicator display cannot be enabled while the watch’s battery is
low.
Pressure Sensor and Temperature Sensor Calibration
The pressure sensor and temperature sensor built into the watch are calibrated at the factory and normally
require no further adjustment. If you notice serious errors in the pressure readings and temperature
readings produced by the watch, you can calibrate the sensor to correct the errors.
Important!
• Incorrectly calibrating the barometric pressure sensor can result in incorrect readings. Before
performing the calibration procedure, compare the readings produced by the watch with those of
another reliable and accurate barometer.
• Incorrectly calibrating the temperature sensor can result in incorrect readings.
Carefully read the following before doing anything.
–
Compare the readings produced by the watch with those of another reliable and accurate thermometer.
– If adjustment is required, remove the watch from your wrist and wait for 20 or 30 minutes to give the
temperature of the watch time to stabilize.
E-53
To calibrate the pressure sensor and the temperature sensor
1. Take a reading with another measurement device to determine the
exact current barometric pressure or temperature.
2. With the watch in the Timekeeping Mode or in any of the sensor
modes, press
B
to enter the Barometer/Thermometer Mode.
3. Hold down
E
for at least two seconds.
SET Hold
will fl
display and then
TEMP
will appear in the upper display. Keep
E
depressed until
TEMP
appears.
• The c
disp
4. Press
D
to move the fl
barometric pressure value, to select the one you want to calibrate.
5. Use
A
(+) and
C
(
–
) to select the temperature and barometric
pressure value display units as shown below.
Temperature 0.1°C (0.2°F)
Barometric Pressure 1 hPa (0.05 inHg)
• T
setting, press
A
and
C
at the sOFF will appear
the fl
default value.
6. Press
E
to return to the Barometer/Thermometer Mode screen.
E-54
Barometer and Thermometer Precautions
• The pressure sensor built into this watch measures changes in air pressure, which you can then apply
to your own weather predictions. It is not intended for use as a precision instrument in offi
prediction or reporting applications.
• Sudden temperature changes can affect pressure sensor readings. Because of this, there may be
some error in the readings produced by the watch.
• Temperature reading are affected by your body temperature, direct sunlight, and moisture. To achieve
a more accurate temperature reading, remove the watch from your wrist, place it in a well ventilated
location out of direct sunlight, and wipe all moisture from the case. It takes approximately 20 to 30
minutes for the case of the watch to reach the surrounding temperature.
E-55
Using the Altimeter Mode
The watch takes altitude readings and displays results based on air pressure measurements taken by a
built-in pressure sensor.
• The displayed altitude reading is a relative altitude that is calculated based on measurement of
changes in barometric pressure by the watch’s pressure sensor. This means that barometric pressure
changes can cause readings taken at different times at the same location to be different. Also note that
the value displayed by the watch may be different from the actual elevation and/or sea level elevation
indicated for the area where you are located.
• When using the altimeter of this watch for mountain climbing or other activities, it is highly
recommended that you check a map, local altitude indications, or some other source for your current
correct altitude and regularly calibrate the altimeter with the latest information.
Important!
• See “To specify a reference altitude value” (page E-61) and “Altimeter Precautions” (page E-71) for
information about how to minimize differences between readings produced by the watch and values
provided by local altitude (elevation) indications.
Getting Ready
Before actually taking an altitude reading you need to select an altitude screen format and select an
altitude reading interval.
Operation Guide 3444
