Hi - I have found the answer to the second question - how doctors used the dofferent variants but not sure if Heuer made anything other than "base 15 pulsation" during the pre Carrera era.

: Hi,

: I was reading through the register and had some questions about the
: Heuer pulsations chronograph. I wondered if anyone could help?

: The 1950s Heuer pulsations that were listed all seemed to have
: "Calcule sur 15 pulsations" on the dial. I happened to
: come across an image of a Heuer with "base 30
: pulsations" on the dial. I wondered if this might be fake
: or if Heuer did produce Pulsations in 15, 30 and 50 variants?

: I understand that pulsations were used by doctors to
: monitor/measure heart rate but why were different variants of
: pulsations produced and how did they differ in there use?