Cal. 9 CH is a 19 ligne chronograph pocket watch movement from Robert Frères (later called Minerva). It was descended from Cal. 19/3, the company’s first stem-set movement, and shares with the time-only Cal. 9 and Cal. 19/27. It was introduced around 1908 and remained in production through the 1940s.
The company calls it “Chronographe-Compteur Calibre 19/9 CH” in data sheets. It was produced in monopusher (with 6 columns) or 2-pusher (with 7 columns) versions as well as with 30 or 45 minute counters. A non-chronograph version is simply called Cal. 9 or Cal. 19/9.
One distinctive element of the movement is the u-shaped arm for the oscillating pinion, which is unlike anything on any other movement. This makes Cal. 19/9 CH instantly recognizable.
Cal. 3 spawned a range of related pocket watch movements:
| Cal. 19/3 | Open face pocket watch |
| Cal. 19/9 | Open face pocket watch |
| Cal. 19/27 | Open face pocket watch |
| Cal. 19/9 CH | Crown operated chronograph |
| Cal. 19/10 | Pusher operated chronograph |
| Cal. 19/11 | Pusher operated split seconds chronograph |