Barometer/Thermometer; Altimeter - Casio GDF100-1A Operation Manual

Operation Guide 3255
Note
• For information about selecting a Home City and confi guring the DST setting, see
"Confi guring Home City Settings" (page E-14).
• While 12-hour format is selected for timekeeping, a P (PM) indicator will appear for
times from noon to 11:59 p.m. No indicator appears for times from midnight to
11:59 a.m. With 24-hour format, time is displayed from 0:00 to 23:59, without any P
(PM) indicator.
• The watch's built-in full automatic calendar makes allowances for different month
lengths and leap years. Once you set the date, there should be no reason to
change it except after you have the watch's battery replaced.
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2. Press fi ve times to return to the Timekeeping Mode.
• The watch will return to the Timekeeping Mode automatically if you do not
perform any operation for about one hour after entering the Barometer/
Thermometer Mode.
Barometric Pressure
• Barometric pressure is displayed in units of 1 hPa (or 0.05 inHg).
• The displayed barometric pressure value changes to - - - if a measured barometric
pressure falls outside the range of 260 hPa to 1,100 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
• Temperature is displayed in units of 0.1°C (or 0.2°F).
• The displayed temperature value changes to --.- °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.
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Reading Barometric Pressure Differential Pointer
Pressure differential is indicated in the
range of ±5 hPa, in 1-hPa units.
If the pointer is
It means this:
located here:
Pressure is falling and
–
weather will tend to
deteriorate.
Pressure is rising and
+
weather will tend to
improve.
• The nearby screen shot, for example,
shows what the pointer would indicate
when the calculated pressure differential
is approximately – 3 hPa (approximately
–0.09 inHg).
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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, press
enter the Barometer/Thermometer Mode.
3. Hold down
to fl ash on the display. This is the setting screen.
• Before the temperature value starts to fl ash, the
message SET Hold will appear on the display.
Keep depressed until SET Hold disappears.
4. Press to move the fl ashing between the temperature
value and barometric pressure value, to select the one
you want to calibrate.
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Altimeter

The watch displays altitude values based on air pressure readings taken by a built-in
pressure sensor.
How the Altimeter Measures Altitude
The altimeter can measure altitude based on its own preset values (initial default
method) or using a reference altitude specifi ed 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.
When you measure altitude using a reference altitude specifi ed by you
After you specify a reference altitude, the watch uses
that value to convert barometric pressure readings to
altitude (page E-32).
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Current pressure greater than Current pressure greater than
most recent measured pressure most recent measured pressure
inHg values inHg values
hPa values hPa values
0 0 0 0
hPa values hPa values
inHg values inHg values
Current pressure less than most Current pressure less than most
recent measured pressure recent measured pressure
to
until the current temperature value starts
B B
A A

Barometer/Thermometer

This watch uses a pressure sensor to measure air pressure (barometric pressure) and
a temperature sensor to measure temperature.
To enter and exit the Barometer/Thermometer Mode
Pressure differential Pressure differential
pointer pointer
1. While in the Timekeeping Mode, press
Current time Current time
Barometer/Thermometer Mode.
• BARO will appear on the display, indicating
that barometric pressure and temperature
measurements are in progress. The measurement
results will appear on the display after about fi ve
seconds.
• After you press
every fi ve seconds for the fi rst three minutes, and
then every two minutes after that.
Barometric Barometric Temperature Temperature
pressure pressure
Display Units
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 specify temperature, barometric
pressure, and altitude units" (page E-37).
Barometric Pressure Differential Pointer
This pointer indicates the relative difference between the
Barometric Barometric
most recent barometric pressure reading and the current
pressure pressure
barometric pressure value displayed in the Barometer/
differential differential
pointer pointer Thermometer Mode (page E-21).
• 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).
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
a sensor to the reading of another device to correct the errors.
Important!
• 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.
5. Use (+) and (–) to adjust the calibration value in the units shown below.
Temperature 0.1°C (0.2°F)
Barometric Pressure 1 hPa (0.05 inHg)
• To return the currently fl ashing value to its initial factory default setting, press
and at the same time. OFF will appear at the fl ashing location for about
one second, followed by the initial default value.
6. Press to return to the Barometer/Thermometer Mode screen.
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 cial weather prediction or reporting applications.
• Sudden temperature changes can affect pressure sensor readings.
• Temperature measurements are affected by your body temperature (while you are
wearing the watch), direct sunlight, and moisture. To achieve a more accurate
temperature measurement, 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 actual
surrounding temperature.
• When mountain climbing, you can specify a reference altitude value in accordance
with a marker along the way or altitude information from a map. After that, the
altitude readings produced by the watch will be more accurate than they would
without a reference altitude value.
To take an altimeter reading
1. Make sure the watch is in the Timekeeping Mode.
Current time Current time
2. Press to start Altimeter measurement.
• ALTI will appear on the display, indicating that
Altimeter measurement is in progress. The fi rst
reading will appear on the display after about four
or fi ve seconds.
• The current altitude value is displayed in units of 5
meters (20 feet).
• After the fi rst reading is obtained, the watch
continues to take altimeter readings automatically
Current altitude Current altitude
every fi ve seconds for the fi rst three minutes, and
then every two minutes after that.
Temperature Temperature
to enter the
, the watch will take readings
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