Sinn Instrument Chronographs watches

Sinn's Instrument Chronographs are the Frankfurt brand's pilot's, sports and space chronographs. Helmut Sinn, a Luftwaffe pilot and flight instructor, founded the company in 1961 to make navigation cockpit clocks and pilot's chronographs; Lothar Schmidt bought it in 1994.

The 103 has been in Sinn's catalogue since the 1960s, its number marking the brand's third chronograph, and the 1970s 103 C ran on a Valjoux 726. It is a 41 mm case with a 60-minute countdown bezel, in steel or titanium; the 103 Ti TESTAF uses a Valjoux 7750. The suffixes name Sinn's technologies. Ar is the dehumidifying system introduced in 1998: a copper sulphate capsule binds moisture to slow the ageing of the oils. DIAPAL, from 2001, uses diamond pallets so the escapement needs no oil. TESTAF is the pilot's watch standard developed at Aachen University of Applied Sciences with Sinn and introduced in 2012, and the IFR models carry DIN 8330, the 2016 standard built on it. A 103 Ti Ar took first place in its class at the 1998 Goldene Unruh.

The 356 is a 38.5 mm two-register pilot's chronograph and the 358 a 42 mm pilot's chronograph. The 144 is Sinn's sports chronograph, the 900 a 44 mm pilot's model whose 900 Pilot took first place at the 2010 Goldene Unruh. The Duochronograph 756, at 40 mm, introduced the Tegiment surface hardening in 2003; the 43 mm 757 adds a diver's bezel and comes in UTC versions. The EZM 10 TESTAF is 46.5 mm and runs on the SZ01, a Valjoux 7750 extensively modified by Sinn with a central elapsed-minute counter and a 24-hour indicator, and works from minus 45 to plus 80 degrees Celsius.

The 44 mm Space Chronographs 140 St and 140 St S share their number with the 140 S that Reinhard Furrer wore on the Spacelab D1 mission in 1985, one of the first automatic chronographs used in space; it ran on a Lemania 5100. The 140 St uses the SZ01, developed from 2003 on the model of the Lemania 5100.