Casio 2891 Taking Altitude Readings, What can I do with altitude readings, Interpreting the Altitude Differential Graphic, ❚To take an altitude reading

Operation Guide 2891

Taking Altitude Readings

❚To take an altitude reading

In the Timekeeping Mode, Compass Mode, or Pressure/Temperature Mode, press the C button to enter the Altitude Mode. The watch will measure your current altitude and display it.

The watch uses International Standard Atmosphere (ISA) values that are defined by the International Civil Aviation Organization (ICAO) to convert readings taken by its built-in pressure sensor to relative altitude values.

Important!

When taking altitude readings, make sure that the temperature of the watch is kept as stable as possible, and is not affected by changes in temperature. You can do this by keeping the watch in direct contact with your skin.

•Variation in the watch’s temperature due to changes in air temperature or altitude can cause altitude reading error.

Altitude Mode Display

Altitude Graph ACT Indicator

Altitude

Display Range: –10,000 to 10,000 meters

Display Unit: 5 meters

Measurement Range: –700 to 10,000 meters

Measurement Unit: 5 meters

•	Though the display range covers 20,000 meters (from –10,000 to
	10,000), the measurement range covers only 10,700 meters
	(–700 to 10,000).
•	The altitude values produced by the watch are relative altitude

What can I do with altitude readings?

Example 1: Find out how high you have hiked or climbed.

Start an altitude reading operation at the foot of the mountain as you start off, and find out how many meters you climbed when you get to the top.

Example 2: Determine how high above sea level your house is. When you travel from your home to

Example 3: Measure how tall a building is.

Set the altitude to zero on the first floor of a building, and then go up to the top floor to measure how tall it is.

•Note that pressurizing and ventilation equipment inside of some buildings can cause errors in altitude readings.

Current Time

•The altitude can take up to four or five seconds to appear after you enter the Altitude Mode.

Altitude Tendency Graph

The altitude tendency graph shows	Current altitude (flashing)
past altitude values measured in the
past altitude values measured in the
Altitude Mode.

•Each plot on the graph

represents 10 meters.

values. This means they are relative to a reference altitude value

that you preset. Even when you are at a location that is above sea

level, the watch may display a negative value (indicating you are

currently lower than your reference value).

• The display shows “– – –” when the measured value is outside the

measurement range or display range.

If you do not perform any button operation for nine or ten minutes while in the Altitude Mode, the watch will return to the Timekeeping Mode automatically.

the beach, you can measure the relative change in altitude and determine how high your home is above sea level.

Altitude Readings

After you enter the Altitude Mode, the watch takes readings every five seconds for three minutes (ACT indicator flashing). After that, readings are taken every two minutes (ACT indicator displayed, without flashing).

Interpreting the Altitude Differential Graphic

❚To turn the altitude differential graphic on and off

The altitude differential graphic shows the relative difference between consecutive values measured in the Altitude Mode, so you can monitor changes as you ascend or descend.

•The graphic shows changes up to ±15 meters in 5-meter units.

•You can turn display of the altitude differential graphic off, if you want.

Example 1: Altitude Differential: –10 meters

+15m

±0m

Altitude Differential

Graphic (–10 meters)

–15m

Example 2: Altitude Differential: +15 meters

Altitude Differential Graphic (+15 meters)

In excess of ±15 meters

Graphic displayed at 9 o’clock

Indicator appears at 9 o’clock

1. In the Altitude Mode, hold down the Ebutton for about two seconds until “SET” appears at the top of the display.

• After about four or five

seconds, the altitude value

will appear in the middle of (2 seconds) the display.

2. Press the D button twice to move the flashing to the altitude differential graphic On/OFF setting.

(Twice)

3.	Reference altitude
3.	Press the Cbutton to
	toggle the setting on
	(display graphic) and off
	(do not display graphic).

4. Press the Ebutton to exit the setting screen and return to the Altitude Mode screen.

•The watch automatically exits the altitude differential graphic on/ off setting screen if you do not perform any operation for about two or three minutes.