Citizen 7240 Instruction Manual

CITIZEN QUARTZ
Analog Alti-Meter
Model No. AY6❈❈❈
Caliber No. 7240
• INSTRUCTION MANUAL
CTZ-B6771
Thank you very much for purchasing a CITIZEN
QUARTZ WATCH. To ensure correct use, please
read these instructions carefully. Please ensure that
the Citizen international guarantee card is supplied
with watch on purchase, that you may claim the
guarantee service (subject to the terms of guarantee).
Precautions for use
This watch is not a measuring instrument authorised
by official authorites.Do not use the altimetry function
to judge situation involving danger.The following
precautions should be adequately understood before
using the altimeter. Please remember that the
Altimetry function should be used only as general
reference.
1. Do not use the Altimetry Function When...
The altimetry should not be used in the following
situations:
• When judging your actions or situation involving
danger in an environment where the temperature
changes drastically.
• In an environment where pressure is subject to
change, such as in an airplane or building (correct
measurement cannot be obtained).
• When the altitude changes greatly within a short time.
• In case of special handling other than normal use,
not described in this manual.

2. Altimetry Function

The altitude displayed by this watch is relative to
altitude based on the sensored air pressure and "The
international standard atmospheric pressure and
altitude". Therefore, display of measured altitude
will change if air pressure changes, even if
measurement is made in the same place. the time
display from measurement to display of altitude is
approximately 5 seconds (in continuosly altimetry
mode). Therefore, this altimetry function may not be
used in sports as skydiving, etc., where altitude
changes greatly within a short time. After 30 minutes,
Continuous Altimetry Mode will automatically change
to Altimetry Mode in which every measurement is
made every hour. To resume Continuous Altimetry
Mode, operate the watch as explained in the instruction
manual. In order to efficiently use the altimetry function
of this watch, the altitude must always be corrected
for your location, clearly indicated with the altitude.

3. Pressure Sensor

Do not disassemble the pressure sensor used in this
watch or poke it with a thin rod. Take care that no
dust enters the pressure sensor.

4. Battery

Battery life will maintain accuracy for about 2 years
under normal conditions after installing a new battery.
However, the battery life will change depending on the
frequency that the altimetry, chronograph are used.
Thus, early replacement of the battery is
recommended.
A. Basic Functions of the Altimeter
This watch is designed to calculate altitude from
changes in air pressure by using the relationship
between air pressure and altitude, based on the
conditions for standard correct atmosphere*
specified by the International Civil Aviation
Organisation (ICAO). To obtain correct altitude on the
watch, altitude must be aligned with an accurate point
(triangulation station or benchmark). Such operation
is called "Compensating the altitude" (see page 12)
* Standard atmosphere: ICAO Standard Atmosphere
adopted by the ICAO in 1964, whereby 1013.25 hPa
at 15°C is specified as elevation 0. However, air
pressure continuosly changes at any given place.
This watch's operating is based on ISA standards.
The following chart provides an outline of ISA
standard configurations.
(from International Standard Atmospheric)
Altitude (m) Atmospheric
Pressure (hPa)
5,000 540.2
4,000 616.4
3,000 701.1
2,000 795.0
1,000 898.7
0 1,013.25
Temp ( o C) Temp diff.
every 1,00
-17.5
-11.0
-4.5 Approx.
2.0 6.5 o C
8.5
15.0