6
Operation Guide 3173 3246
Using the Altitude Differential Value While Mountain Climbing or Hiking
After you specify the altitude differential start point while mountain climbing or hiking, you easily can
measure the change in the altitude between that point and other points along the way.
To use the altitude differential value
1. In the Altimeter Mode, check to make sure that an altitude reading is
on the display.
• If an al titude re ading is no t displayed, p ress
A
to take o ne. Se e “T o
take a n altim eter reading ” for deta ils.
2. Use the contour lines on your map to determine the difference in
altitude between your current location and your destination.
3. In the Altimeter Mode, press
E
to specify your current location as the
altitude differential start point.
• The watc h will take a n altitu de reading a nd registe r the resul t as
the altitude differential v alue start point. The altitude differential
value w ill be reset to ze ro at this ti me.
4. While comparing the altitude difference you determined on the map
and the watch’s altitude differential value, advance towards your
destination.
• If the m ap shows t hat the di fferen ce in alti tude bet ween yo ur
lo cation a nd your de stinati on is +8 0 meters fo r example, y ou know
you wi ll be near ing your de stinati on when t he displaye d altitu de
dif ferentia l value sho ws +80 m eters.
Specifying a Reference Altitude Value
The altitude readings produced by this watch are subject to error caused by changes in air pressure.
Because of this, we recommend that you update the reference altitude value whenever one is available
during your climb. After you specify a reference altitude value, the watch adjusts its air-pressure-to-altitude
conversion calculation accordingly.
To specify a reference altitude value
1. In the Altimeter Mode, hold down
E
until the current reference altitude
value starts to fl ash. This is the setting screen.
• Before t he referenc e altitu de value st arts to fl ash , the mes sage
SET H ol d will appe ar on the di splay. Keep
E
depre ssed un til
SET Hold disappears.
2. Press
A
(+) or
C
(–) to change the current reference altitude value
by 5 meters (or 20 feet).
• Spe cify a refe rence alt itude valu e based on a ccurate alt itude
info rmatio n about yo ur curren t locati on from a m ap, etc.
• Y ou c an set the refe rence alt itude val ue within t he range of –10,0 0 0
t o 1 0 , 000 m e t er s ( –32 ,800 t o 32 , 800 fe e t ) .
• Pressing
A
and
C
at the s ame tim e returns t o OFF (no referenc e
alti tude value), so th e watch per forms ai r pressure to al titude
conve rsion s based on p reset data o nly.
3. Press
E
to exit the setting screen.
Types of Altitude Data
The watch can maintain two types of altitude data in its memory: manual measurement records, and auto
save values (minimum, maximum, vertical ascent, vertical descent).
• Use the Data Recall Mode to view data stored in memory. See “Viewing Altitude Records” for details.
Manual Measurement Records
Any time you perform the procedure below in the Altimeter Mode, the watch will create and store a record
with the currently displayed altitude reading, along with the date and time the reading was taken. There is
enough memory to store up to 25 manual measurement records, which are numbered from
REC01
through
REC25
.
To save a manual measurement
1. In the Altimeter Mode, check to make sure that an altitude reading is
on the display.
• If an al titude re ading is no t displayed, p ress
A
to take o ne. Se e “T o
take a n altim eter reading ” for deta ils.
2. Hold down
A
until
REC Hold
appears on the display and then
disappears. Release
A
after
Hold
disappears.
• Thi s will save th e currentl y displayed al titude re ading in a ma nual
mea sureme nt record, a long wi th the mea sureme nt time an d date.
• The wa tch will retur n to the Alti meter Mo de screen a utomati cally
af ter the save op eration i s comple te.
• The re is enou gh memo ry to sto r e up to 2 5 manual m easurem ent
reco rds. If th ere are alread y 25 manu al meas urement re cords in
mem ory, the ab ove operat ion will c ause the o ldest rec ord to be
dele ted automa tically to m ake room fo r the new on e.
Auto Save Values
Two sets of auto save values (Set 1 and Set 2) are maintained in watch memory.
Set 1 Set 2
Maximum Altitude (
MAX-1
)
Minimum Altitude (
MIN-1
)
Vertical Ascent (
ASC-1
)
Vertical Descent (
DSC-1
)
Maximum Altitude (
MAX-2
)
Minimum Altitude (
MIN-2
)
Vertical Ascent (
ASC-2
)
Vertical Descent (
DSC-2
)
• These values are checked and updated automatically by the watch as altitude auto measurements are
taken.
How Maximum and Minimum Values Are Updated
While the watch is in the Altimeter Mode, altitude readings are taken automatically at the interval specifi ed
by the altitude auto measurement method. With each reading, the watch compares the current reading
against the
MAX
(
MAX-1
and
MAX-2
) and
MIN
(
MIN-1
and
MIN-2
) values. It will replace the
MAX
value if
the current reading is greater than
MAX
, or the
MIN
value if the current reading is less than
MIN
.
How Vertical Ascent/Descent Values Are Updated
Session start point
20 m
0 m
120 m
320 m
620 m
Session end point
The total Vertical Ascent and Vertical Descent values produced by an Altimeter Mode measurement
session during the example climb illustrated above are calculated as follows.
Vertical Ascent:
(300 m) +
(620 m) = 920 m
Vertical Descent:
(320 m) +
(500 m) = 820 m
Current
location
Destination
altitude
Current
location
Destination
altitude
Altitude differential
Altitude
Altitude differential
Altitude
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
• Entering the Altimeter Mode starts a new altitude auto measurement session, but it does not reset the
current
ASC
(
ASC-1
and
ASC-2
) and
DSC
(
DSC-1
and
DSC-2
) values or change them in any way.
This means that the starting
ASC
and
DSC
values for a new Altimeter Mode auto measurement session
are the values that currently are in memory. Each time you complete an Altimeter Mode auto
measurement session by returning to the Timekeeping Mode, the vertical ascent value of the current
session (920 meters in the above example) is added to the session’s starting
ASC
value. Also, the
vertical descent value of the current auto measurement session (
–
820 meters in the above example) is
added to the session’s starting
DSC
value.
• Note that any change in elevation when ascending that is less than 15 meters (49 feet) is not added to
the vertical ascent value for the current Altimeter Mode auto measurement session. Also, any change in
elevation when descending that is less than
–
15 meters (
–
49 feet) is not added to the vertical descent
value for the current Altimeter Mode auto measurement session.
Note
• The maximum altitude, minimum altitude, vertical ascent, and vertical descent values are retained in
memory when you exit the Altimeter Mode. To clear values, perform the procedure under “To clear the
contents of a specifi c memory area”.
Using Auto Save Values
The watch maintains two independent sets of auto save values as shown below.
Set 1 Set 2
Maximum Altitude (
MAX-1
)
Minimum Altitude (
MIN-1
)
Vertical Ascent (
ASC-1
)
Vertical Descent (
DSC-1
)
Maximum Altitude (
MAX-2
)
Minimum Altitude (
MIN-2
)
Vertical Ascent (
ASC-2
)
Vertical Descent (
DSC-2
)
The values in Set 1 and Set 2 can be cleared independently of each other. This means you can use them
to keep track of daily and cumulative data as described in the example below.
Example:
Keeping track of data on a three-day climb
Day 1
Clear both Set 1 and Set 2, and start your Day 1 climb.
At the end of the day, both sets of auto save values contain the same data (
MAX-1
=
MAX-2
,
MIN-1
=
MIN-2
, etc.).
Day 2
Clear only Set 1, and start your Day 2 climb. At the end of the day, the values in Set 1 (
MAX-1
,
MIN-1
,
ASC-1
,
DSC-1
) will show the results of Day 2 only. In Set 2,
MAX-2
and
MIN-2
will show the maximum
and minimum altitudes reached over the two-day span.
ASC-2
will show the total vertical ascent for the
two days (Day 1 + Day 2) and
DSC-2
will show the total vertical descent for the two days.
Day 3
Clear only Set 1, and start your Day 3 climb. At the end of the day, the values in Set 1 will show the
results of Day 3 only. In Set 2,
MAX-2
and
MIN-2
will show the maximum and minimum altitudes
reached over the three-day span.
ASC-2
will show the total vertical ascent for the three days (Day 1 +
Day 2 + Day 3) and
DSC-2
will show the total vertical descent for the three days.
• For details about clearing altitude data, see “To clear the contents of a specifi c memory area”.
How does the altimeter work?
Generally, air pressure and temperature decrease as altitude increases. This watch bases its altitude
measurements on International Standard Atmosphere (ISA) values stipulated by the International Civil
Aviation Organization (ICAO). These values defi ne relationships between altitude, air pressure, and
temperature.
0 m
500 m
1000 m
1500 m
2000 m
2500 m
3000 m
3500 m
4000 m
899 hPa
795 hPa
701 hPa
616 hPa
8.5°C
2°C
–4.5°C
–11°C
15°C 1013 hPa
About 6.5°C
per 1000 m
About 8 hPa per 100 m
About 9 hPa per 100 m
About 10 hPa per 100 m
About 11 hPa per 100 m
About 12 hPa per 100 m
Altitude Air Pressure Temperature
0 ft.
2000 ft.
4000 ft.
6000 ft.
8000 ft.
10000 ft.
12000 ft.
14000 ft.
25.84 inHg
22.23 inHg
19.03 inHg
44.7°F
30.5°F
16.2°F
59.0°F29.92 inHg
About 3.6°F
per 1000 ft.
About 0.15 inHg per 200 ft.
About 0.17 inHg per 200 ft.
About 0.192 inHg per 200 ft.
About 0.21 inHg per 200 ft.
Source: International Civil Aviation Organization
• Note that the following conditions will prevent you from obtaining accurate readings:
When air pressure changes because of changes in the weather
Extreme temperature changes
When the watch itself is subjected to strong impact
There are two standard methods of expressing altitude: Absolute altitude and relative altitude. Absolute
altitude expresses an absolute height above sea level. Relative altitude expresses the difference between
the height of two different places.
Height of building 130 m
(relative altitude)
Rooftop at an altitude of
230 m above sea level
(absolute altitude)
Sea Level
Altimeter Precautions
• 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 is also affected by
temperature. When taking altitude measurements, do not subject the watch to temperature changes.
• 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 fl ight crew.