CASIO PRT71B-3
Owner's Manual

2307/2335/2355/2357-4
Selecting the measurement unit
1. Use C to enter the Altimeter Mode. 2. Hold down A until �OFF� or the current reference altitude value flashes on the display. 3. Press C to change to the measurement unit selection screen. 4. Each press of D or B toggles the altitude measurement unit as shown below.
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Selecting the measurement unit
1. Use C to enter the Thermometer Mode. 2. Hold down A until �OFF� or the current temperature calibration value flashes on the display. 3. Press C to change to the measurement unit selection screen. 4. Each press of D or B toggles the temperature measurement unit as shown below.
°C °F

5. After you select the measurement unit you want, press A to return to the Altimeter Mode screen. � Note that all measurement data currently in memory is also deleted whenever you change the barometric pressure, altitude, or temperature unit of measurement

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5. After you select the measurement unit you want, press A to return to the Thermometer Mode screen. � Note that all measurement data currently in memory is also deleted whenever you change the barometric pressure, altitude, or temperature unit of measurement.

Setting a reference altitude
After you set a reference altitude, the watch automatically calculates the difference between the current altitude and your preset value. The altitude measurements produced by this watch are subject to error caused by changes in barometric pressure. Because of this, we recommend that you set the reference altitude during your climb whenever one is available. 1. Use C to enter the Altimeter Mode. 2. Hold down A until �OFF� or the current reference altitude value flashes on the display. � �OFF� appears when the factory setting is currently set as the reference altitude value. 3. Each press of D increases the displayed altitude by 5 m, while pressing B decreases it. Holding down either button changes the value at high speed. � If you have selected feet as your unit of measurement, the above operations change the reading by 20 feet. � You can set the reference altitude within the range of �6,000 meters to 6,000 meters (�19,680 feet to 19,680 feet). � Pressing B and D at the same time returns to the �OFF� setting. 4. After setting the reference altitude you want, press A to return to the Altimeter Mode screen.

Calibrating the temperature measurement
The temperature sensor of this watch is calibrated at the factory before shipment, and further adjustment is normally not required. If noticeable error is found in the temperature readings produced by the watch, you can adjust it to correct the error. Important! Incorrectly calibrating the temperature measurement of this watch can result in incorrect readings. Carefully read the following before doing anything. � Compare the readings produced by the watch with those of another reliable, 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.

Calibrating the temperature

THERMOMETER MODE
A built-in temperature sensor measures temperature and shows the measured value on the display. The thermometer can be calibrated to correct for errors. Important! 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 off all moisture from the case. It takes approximately 20 to 30 minutes for the case of the watch to reach the temperature of the surrounding air.

1. Use C to enter the Thermometer Mode. 2. Hold down A until �OFF� or the current temperature calibration value flashes on the display. � �OFF� appears when the factory setting is currently set as the current temperature calibration value. 3. Each press of D increases the displayed temperature by 0.1°C, while pressing B decreases it. Holding down either button changes the value at high speed. � If Fahrenheit is currently selected as the unit of measurement, the above operations change the reading by 0.2°F. � Pressing B and D at the same time returns to the �OFF� setting. 4. After calibrating the temperature, press A to return to the Thermometer Mode screen.

MEMORY
The watch is equipped with memory that you can use to store up to 10 barometric pressure, altitude, and temperature readings. Note that the date and time of the measurement is not included with the data. The number of available blank records that can be used to store data is shown on the right side of the Barometer, Altimeter, and Thermometer Mode screens.

About temperature measurements
The watch takes temperature measurements every five seconds for the first two minutes after you enter the Thermometer Mode. The Thermometer Mode indicator 1 flashes on the display during these two minutes. After the first two minutes, the Thermometer Mode indicator 1 stops flashing, and the watch automatically takes measurements every five minutes.

Storing a Measurement
While in the Barometer, Altimeter, or Thermometer Mode, hold down D for about one second until the watch beeps, indicating that the latest measurement is stored in memory. � The message �FULL� appears on the display for about one second when you hold down D while memory is full. No more data can be stored while memory is full. � If you want to store more data after memory becomes full, use the procedure under �Recall Mode� below to delete the current data to make room for new data.

Understanding the temperature display
The display shows �� � . � °C� (or °F) if a measured value falls outside the range of �10.0°C to 60.0°C (14.0°F to 140.0°F). The normal display will return as soon as the temperature returns within the allowable range.
Thermometer Mode indicator 1
A

Temperature
2 seconds B later

Unit of measurement

18 5
E NP

C

D

Remaining memory Thermometer Mode indicator 2

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18 5

Temperature graph

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Press A.