A pulsometer scale is a scale on some chronograph watches that is used to read off a person’s heart rate. The wearer times a fixed number of beats and reads the rate from the scale. It was most popular in the early to mid-1900s, mainly with medical staff and athletes.
How do you use a pulsometer scale?
Start the chronograph on one heartbeat. Count the beats that follow, and stop the chronograph when the count reaches the number the scale is set for. The heart rate is then read from the scale at the point where the chronograph hand has stopped. Most scales are calibrated for a count of either 15 or 30 beats. A wristwatch with a pulsometer scale is known as a doctor’s chronograph, and on these the scale may also be set for 20 beats. The count must match the scale, or the reading will be wrong.
Where it comes from
The English physician Sir John Floyer is credited with the first commercially available pulse watch. His pulse watches were built by the horologist Samuel Watson. In the early 1920s, Swiss watchmakers began adding scales to make pulse readings faster and more reliable. Longines, Omega, Universal Genève and Heuer all made pulsometer watches. Omega first released its Speedmaster Pulsometer model in 1959. The scale has not disappeared. Longines, Blancpain, Montblanc and Vacheron Constantin still make traditional pulse watches.
Not to be confused with
A pulsometer and a tachymeter measure different things. A tachymeter works out speed over a known distance. A pulsometer measures a biological rhythm, namely the heartbeat. That sets it apart from scales that measure speed or distance. The tachymeter needs a measured course to work from. The pulsometer needs only a counted number of beats and a chronograph to time them.
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