Casio 2891 Calibrating the Pressure Sensor, Calibrating the Temperature Sensor, Barometric Pressure Primer, ❚Ways you can use the pressure tendency graph

Operation Guide 2891

Calibrating the Pressure Sensor

The barometric pressure sensor of the watch is calibrated at the factory, and further calibration normally is not required. Perform the following operation only when you find that a pressure reading taken with another accurate instrument is very different from the reading produced by your watch. Take care that you perform the calibration operation correctly. Using the wrong value can make it impossible to measure barometric pressure correctly.

Calibrating the Temperature Sensor

The temperature sensor is calibrated at the factory, and further calibration normally is not required. Perform the following operation only when you find that a temperature reading taken with another accurate instrument is very different from the reading produced by your watch. Take care that you perform the calibration operation correctly. Using the wrong value can make it impossible to measure temperatures correctly.

1.	In the Pressure/	Pressure
	Temperature Mode, hold
	down the E button for
	about two seconds until
	“OFF” or the current
	temperature appears at
	the bottom of the display.
•	It will take four to five seconds
	for the barometric pressure	(2 seconds)
	value to appear.	Temperature

2. Press the Dbutton so “OFF” or the barometric pressure value is flashing.

3. Use the C(+) and A(–) buttons to adjust the barometric pressure value.

•	Each press of the Cbutton
	or Abutton changes the
	displayed value by 1hPa.
•	Holding down either button
	scrolls the setting at high
	speed.
•	Pressing the Cand A
	buttons at the same time
	returns to the factory default
	setting, which is indicated by
	“OFF”.
4.	After the setting is the
	way you want, press the
	Ebutton to return to the
	Pressure/Temperature
	Mode screen.
•	The watch automatically exits

(–)

(+)

1. In the Pressure/	Pressure
Temperature Mode, hold
down the Ebutton for
about two seconds until
“OFF” or the current
temperature appears at
the bottom of the display.

•It will take four to five seconds

for the barometric pressure	(2 seconds)
value to appear.

2. Use the C(+) and A(–) buttons to adjust the temperature value.

•Each press of the Cbutton

or Abutton changes the displayed value by 0.1oC.

•Holding down either button scrolls the setting at high speed.

Temperature

(–)

(+)

3. After the setting is the way you want, press the E button to return to the Pressure/Temperature Mode screen.

•The watch automatically exits the temperature sensor calibration screen if you do not perform any operation for about two or three minutes.

the pressure sensor

calibration screen if you do

not perform any operation for

about two or three minutes.

•Pressing the C and Abuttons at the same time returns to the factory default setting, which is indicated by “OFF”.

Barometric Pressure Primer

❚Ways you can use the pressure tendency graph

Example 1: Hiking

You can take barometric pressure readings from morning to night the day before you plan to go hiking or mountain climbing, and get an idea of what the weather will be like.

Example 2: Golf

Changes in barometric pressure can alert you to an approaching thunderstorm and keep you safe.

❚Predict weather based on changes in barometric pressure.

Barometric pressure changes along with atmospheric movements. Because of this, you can predict upcoming weather by monitoring changes in barometric pressure.

If barometric pressure is rising ➔ Weather conditions should improve

If barometric pressure is falling ➔ Weather conditions should deteriorate

Why this is true

A rise or fall in barometric pressure produces changes in the weather as shown to the right.

High Pressure

Downward flowing air dissipates clouds and clears the skies.

Sky	Low Pressure	Sky	Clouds
	Upward flowing air
	produces clouds,
	which cause rain.

Downward Air Flow	Upward Air Flow
Ground	Ground
High Pressure	Low Pressure

❚Atmospheric Pressure

The barometric pressure values reported on TV, in newspapers, and in other media are actual readings taken on mountains, plains, and the sea, which are converted to a mean sea level pressure value. They are not the barometric pressure values for mountain areas. This makes it possible to compare barometric pressure values regardless of location. The process of correcting barometric pressure to a fixed altitude (sea level) is called “reduction to sea level”.

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