How to use as an altimeter, Altimeter function – CatEye CC-AT100 User Manual

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R e s e t

When the S/S button and the Mode button are pressed simultaneously, the following data can be reset, depending on the mode.

For resetting trip distance(D), elapsed time(T), average speed(A) and maximum speed (M):

In other modes than altitude measuring mode, press the two buttons simultaneously; then the data of D, T, A and M returns to zero.

For resetting the trip altitude gain:

In the sub mode showing the trip altitude gain and total altitude gain, press the two buttons simultaneously; then the data of the trip altitude
gain(

) returns to zero.

For resetting the current altitude correction value:

In the main mode showing the current altitude (

), press the two buttons simultaneously; then the current altitude correction value will be

zero and the data will be reset to the initial value of "International Standard Atmosphere" (ISO 2533).

The Correlation Between Altitude and Pressure

The higher the altitude gets, the lower the pressure becomes. At venues of which altitudes are under 500m, the pressure decreases by approx.
12hPa per each 100m (Table 1).

Weather and Barometric Pressure Changes

Changes in weather from a HIGH PRESSURE system (clearer, calmer weather) to a LOW PRESSURE system (over-cast, rain, storming
weather) can cause a change in the Altitude reading of 300 feet or more. Thunderstorms or other strong low pressure weather conditions, you

Correlation between above sea
level and pressure

extract from ISO 2533 (Table 1)

A.S.Level

Pres.

A.S.Level

Pres.

4500 m 577 hPa

600 m

943 hPa

4000 m 616 hPa

500 m

955 hPa

3500 m 658 hPa

400 m

966 hPa

3000 m 701 hPa

300 m

978 hPa

2500 m 749 hPa

200 m

989 hPa

2000 m 795 hPa

100 m 1001 hPa

1500 m 845 hPa

0 m 1013 hPa

1000 m 899 hPa –100 m 1025 hPa

900 m 910 hPa –200 m 1038 hPa
800 m 921 hPa –300 m 1050 hPa
700 m 932 hPa

HOW TO USE AS AN ALTIMETER

1. Altimeter Function

This unit, loaded with a pressure sensor, measures the altitude by using atmospheric pressure. It esti-
mates the altitude by using the "correlation between altitude and pressure" of ISO 2533, based on the
International Standard Atmosphere of ICAO (International Civil Aviation Organization). Generally, a con-
ventional pressure sensor is affected by temperature and gives errors; but this unit is temperature-com-
pensated every 20 seconds and records 1 meter resolution. Also, with a conventional altimeter, altitude
data at the same venue varies from time to time because it is affected by the change of the pressure;
however, the CATEYE CC-AT100 is not affected by pressure changes when not cycling. It measures three
types of altitude data simultaneously: above sea level (current altitude), trip altitude gain (total of altitude
gain from the start to the current point) and total altitude gain (accumulation).
Note: The current altitude data may give an incorrect value temporarily, such as when it is brought from

indoor to outdoor, or when the energy-saving function is released. This is just an influence of the tem-
perature change and is not a malfunction. It will quickly stabilize and return to normal.

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