Operation Guide 3134 3205
6
Barometer/Thermometer
This watch uses a pressure sensor to measure air pressure (barometric
pressure) and a temperature sensor to measure temperature.
•
You can calibrate the pressure sensor and the temperature sensor if you
suspect that readings are incorrect.
To take barometric pressure and temperature readings
Pressing
B
in the Timekeeping Mode or in any
of other sensor modes enters the Barometer/
Thermometer Mode and starts barometric
pressure and temperature measurements
automatically .
•
It can take up to four or five seconds for the
barometric pressure reading to appear after
you enter the Barometer/Thermometer Mode.
•
Barometric pressure is displayed in units of
1hPa (or 0.05 inHg).
Temperature
Barometric
pressure
Barometric
pressure graph
Pressure
differential
pointer
•
The displayed barometric pressure value changes to
xxxx
hPa (or inHg) if
a measured barometric pressure falls outside the range of 260 hPa to
1100 hPa (7.65 inHg to 32.45 inHg). The barometric pressure value will
reappear as soon as the measured barometric pressure is within the
allowable range.
•
Temperature is displayed in units of 0.1°C (or 0.2°F).
•
The displayed temperature value changes to
xxx
.
x
°C (or °F) if a
measured temperature falls outside the range of –10.0°C to 60.0°C (14.0°F
to 140.0°F). The temperature value will reappear as soon as the measured
temperature is within the allowable range.
•
In some areas, barometric pressure is expressed in millibars (mb) instead
of hectopascals (hPa). It really makes no difference, because 1hPa = 1mb.
•
You can select either hectopascals (hPa) or inchesHg (inHg) as the display
unit for the measured barometric pressure, and Celsius (°C) or Fahrenheit
(°F) as the display unit for the measured temperature value. See “To select
the temperature, barometric pressure, and altitude units”.
•
See “Barometer and Thermometer Precautions” for important precautions.
Barometric Pressure Graph
Barometric pressure indicates changes in the atmosphere. By monitoring
these changes you can predict the weather with reasonable accuracy.
This watch takes barometric pressure measurements automatically every two
hours (at the top of each even-numbered hour), regardless of its current
mode. Measurement results are used to produce barometric pressure graph
and barometric pressure differential pointer readings.
The barometric pressure graph shows readings of previous measurements for
up to 20 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 1hPa.
The following shows how to interpret the data that appears on the barometric
pressure graph.
Barometric Pressure Differential Pointer
This pointer indicates the relative difference between the most recent
barometric pressure reading indicated on the barometric pressure graph and
the current barometric pressure value displayed in the Barometer/
Thermometer Mode.
•
Pressure differential is indicated in the range of ±5 hPa, in 1-hPa units.
•
The barometric pressure differential pointer is not displayed when the
displayed current barometric value is outside of the allowable measurement
range (260 to 1,100 hPa).
•
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.
Pressure differential
examples in the
illustration are indicated
in 3 hPa/0.1 inHg steps.
Current pressure less
than most recent
measured pressure
Current pressure greater
than most recent
measured pressure
Barometric pressure
differential
inHg values
hPa values
About Barometric and Temperature Measurements
•
Barometric pressure and temperature measurement operations are
performed as soon as you enter the Barometer/Thermometer Mode. After
that, barometric pressure and temperature measurements are taken every
five seconds.
•
You also can perform a barometric pressure and temperature measurement
at any time by pressing
B
in the Barometer/Thermometer Mode.
Altimeter
The watch’s altimeter uses a pressure sensor to detect current air pressure,
which is then used to estimate the current altitude based on ISA (International
Standard Atmosphere) preset values. You also can specify a reference
altitude, which the watch will use to calculate your current altitude based on
the value you specify. Altimeter functions also include storage of
measurement data in memory.
Important!
•
This watch estimates altitude based on air pressure. This means that
altitude readings for the same location may vary if air pressure changes.
•
The semiconductor pressure sensor used by the watch for altitude
measurements also is affected by temperature. When taking altitude
measurements, make sure the watch is not subjected to temperature
changes.
•
To avoid the effect of sudden temperature changes during measurement,
keep the watch on your wrist in direct contact with your skin.
•
Do not rely upon this watch for altitude measurements or perform button
operations while sky diving, hang gliding, or paragliding, while riding a
gyrocopter, glider, or any other aircraft, or while engaging in any other
activity where there is the chance of sudden altitude changes.
•
Do not use this watch for measuring altitude in applications that demand
professional or industrial level precision.
•
Remember that the air inside of a commercial aircraft is pressurized.
Because of this, the readings produced by this watch will not match the
altitude readings announced or indicated the flight crew.
How the Altimeter Measures Altitude
The altimeter can measure altitude based on its own preset values, or a
reference altitude specified by you.
When you measure altitude based on preset values
Data produced by the watch’s barometric pressure sensor is converted to
approximate altitude based on ISA (International Standard Atmosphere)
conversion values stored in watch memory.
4. Rotate the bezel so the “N” (North) indicator on the bezel is aligned with
the north indicator produced by the reading in step 3.
5. To advance to your objective proceed in the direction that 12 o’clock is
pointing.
Note
•
When mountain climbing or hiking, conditions or geographic contours may
make it impossible for you to advance in a straight line. If this happens,
return to step 1 and save a new direction to the objective.
•
If you find it difficult to perform the above step while keeping everything
aligned, first move into the correct position (12 o’clock position of the
watch pointed at the objective) without worrying about the orientation of
the map. Next, perform step 1 again to set the map.
3. In the Timekeeping, Digital Compass,
Barometer/Thermometer, or Altimeter Mode,
press
C
to take a compass reading.
•
The compass reading information (angle
value, direction indicator, and four pointers
based on the 12 o’clock position of the
watch) will appear on the display after about
two seconds.
•
The compass reading information will
remain on the display for only about 20
seconds after you press
C
. After that it will
disappear. If you want to re-display the
compass reading information, press
C
again to take another reading.
12 o’clock
position
Direction angle of
current reading
North
pointer
A rising graph generally means improving weather.
A falling graph generally means deteriorating weather.
Note that if there are sudden changes in barometric
pressure or temperature, the graph line of past
measurements may run off the top or bottom of the display.
The entire graph will become visible once barometric
conditions stabilize.
The following conditions cause the barometric pressure
measurement to be skipped, with the corresponding point on
the barometric pressure graph being left blank.
•
Barometric reading that is out of range (260 hPa/mb to 1,100 hPa/mb or
7.65 inHg to 32.45 inHg)
•
Sensor malfunction
Not visible on
the display.
