How to use four different types of chronograph bezels...
Written by Chuck Maddox on 28 March 2000, certain rights reserved.
Last Revised: 31 January 2002, 13:55 GMT
Certain Rights Reserved (c) © 2000-2 Chuck Maddox

View of the Bezel
Bezel Type/Description/Example of Use:

Tachymetre (Tachoproductometric)

Description: Allows one to compute speeds and machine outputs.
Examples of Use:
1) To calculate the speed of a car over a known distance press the top chronograph button when entering the fixed distance press it again when at the end of the fixed distance. If the time elapsed is 45 seconds the second hand points to the figure 80 on the Tachy scale. If the fixed distance is a Kilometer then the car is traveling 80 kilometers per hour. If the distance covered is a mile, then the speed is indicated in Miles per hour, in this example 80 MPH...
2) To calculate the output of a machine, start the chronograph and count a set number of units made, at the end of this number stop the chronograph. If you counted to 100 and the second hand points to 75 on the Tachy ring, the machine's hourly output is 75 times 100 or 7,500 units per hour. 

Telemetric (offered in both kilometers/miles)

Description: The Telemetric scale is graduated to indicate the speed of sound in air. This allows the user to calculate the distance between the observer and a situation that is observable both visually and audibly.

Description of Operation:
On an optical signal, start the chronograph. When you hear the sound stop the chronograph. The number indicated at the distance in kilometers or miles (depending on scale).
Examples of Use:
At the flash of a bolt of lightning start the chronograph. Stopping the chronograph when you hear the thunder (in the case of the diagram at left at 5 Seconds) will indicate on the Telemetre ring 1.6km or 1600 meters away from the wearer of the watch. Sounds like a good time to take cover! =)


Description: The Pulsimetric scale is graduated to indicate the rate of respiration or pulse of a patient. This allows the user to take a pulse or observe a certain number of respirations and read off the correct number of respiration/pulse per minute.

Description of Operation:
The top chronograph button is pressed at the beginning of a pulse or respiration, it is pressed again when the proper number of pulsations/respirations has occurred. The proper number of pulsations is indicated on the bezel dial.
Examples of Use:
At the start of a pulsation the operator starts the chronograph, after the 15th pulse the operator stops the chronograph at 18 seconds. Reading from the stopped second hand to the Pulsimetric scale results in a pulse rate of 50 beats per minute for this patient.


Description: For industrial timing, statistical analysis, calculation of averages and cost prices the use of decimal division of time is common.

Description of Operation:
To measure the length of time it takes to perform any operation start the chronograph when work begins and stop it when the work on the second piece begins. This results in the amount of time to produce a piece.
Examples of Use:
If a worker is fitting a bracelet to a watch, an observer starts the chronograph when the worker begins on a unit to be assembled and stops it when the worker begins on the second unit. The time read off the bezel indicates the time this operation took in hundredths of a minute, in the diagram at left 0.28 minutes per piece.

Statement of rights retained and permissions granted...
Sources included my own research, images gleaned from various sources on the web, Omega Designs book, the Time Capsule book and other Omega Publications and web sites.
The scans are adapted and modified from pictures in the original owners manual for the Omega Speedmaster 125. Special thanks to Simon Debrux for his contributions to this article.
Permission is granted for Damon, RJ, Derek and/or Frank N. to include within the FAQ's they are writing as long as I and the others mentioned in this section and the section above are given credit for their contributions. Permission for personal, educational or non-commercial use is granted. The author retains all other rights not specifically mentioned here.
For all other use please contact the author.
Disclaimer: Opinions are my own and knowing me should be taken with a grain or two of salt...

I hope you find this informational and entertaining. Please contact me if you have corrections,

additions or other comments.

-- Chuck (