Technischer Standard







The EZM 10 and the 103 Ti Ar are the first pilot's watches to meet the TESTAF criteria and to receive certification.

TESTAF represents the first ever standard to define pilot's watches in professional use.

Research project initiated by Sinn Spezialuhren

The Faculty of Aerospace Technology at the Aachen University of Applied Sciences (FH), headed by Prof. Dr.-Ing. Frank Janser, and Sinn Spezialuhren joined forces to develop a technical standard for pilot's watches (TESTAF) in a research project lasting several years. To obtain TESTAF-certification, a pilot's watch must satisfy all time measurement requirements for civil flights operating under visual and instrument flight rules. The EZM 10 and the 103 Ti Ar were the first SINN watches to undergo and pass the strict test procedures.

The project partners: Prof. Dr.-Ing. Frank Janser (left) of Aachen University of Applied Sciences and Lothar Schmidt (Dipl.-Ing.), proprietor of Sinn Spezialuhren.
The TESTAF scientific committee (right to left): Dr. Wolfgang Schonefeld (Sinn Spezialuhren), Dr. Martin Hoch (scientific coordinator), Prof. Dr.-Ing. Frank Janser (Aachen University of Applied Sciences), Martina Richter (Uhren-Magazin), Volker Bau (Dipl.-Ing., Airbus Helicopters), Jürgen Hensiek (Aachen Institute of Applied Sciences e.V.).

The project was proposed by Lothar Schmidt (Dipl.-Ing.), the proprietor of Sinn Spezialuhren, back in 2008. At that time there was no equivalent DIN standard for pilot's watches to that for diver's watches. The partnership saw Sinn Spezialuhren continue its tradition of close collaboration with renowned technological institutions. Its diver's watches, for instance, are tested and certified to European diving equipment standards by DNV GL – a unique procedure in the industry. In the past the DEKRA Technology Center in Klettwitz in Brandenburg tested the ability of various SINN watches to withstand G-forces. The Darmstadt-based Fraunhofer Institute for Operational Stability and System Reliability (LBF) investigated the effects of impact and vibration on specially selected SINN watches on a simulated rough road track. All the watches passed the tests with flying colours. This means that wearers of SINN watches can rest assured that the durability and reliability claims are not just unsubstantiated assertions, but have actually been proven in challenging tests and exacting investigations. The tests are also proof that Sinn Spezialuhren regards its watches as specially developed instruments which are designed to meet particular purpose-related requirements.

TESTAF - a completely new departure

What are the distinguishing features of a professional pilot's watch? Which aviation requirements does it need to fulfil? Which features are indispensable? To provide universally valid answers to these questions it was necessary to formulate a norm or standard. Such a standard did not, however, exist for pilot's watches at that time. And so in 2008 Lothar Schmidt (Dipl.-Ing.), managing director and owner of Sinn Spezialuhren, seized the initiative and decided to close this research gap together with Prof. Dr.-Ing Frank Janser of the Aachen University of Applied Sciences, for years now one of the most respected centres for aerospace technology (the mechanical engineering faculty, to which the aerospace technology department belongs, topped the 2012 university rankings). With its long tradition of developing and testing aerospace instrumentation, the Aachen University of Applied Sciences uniquely combines a strong practical orientation with profound scientific knowledge and flight engineering expertise. The faculty is one of the few in Germany to own its own aircraft; it uses these for teaching, flight laboratory and research purposes. The Aachen University of Applied Sciences is one of the leading teaching and research institutions in Europe in the field of aviation.

Technical progress in watches

The collaboration with the Aachen-based aerospace engineers permitted a number of technical advances in watchmaking to be applied for the first time. Under TESTAF, for example, the low pressure resistance of the watches must be tested more than once. Indeed, they are subjected to several thousand pressure change cycles in order to simulate the actual stress conditions on the wrist of a pilot. Besides being water resistant, a pilot's watch must also be resistant to common aviation fluids such as fuels, hydraulic fluids and cleaning and de-icing agents. In addition, the magnetic field of the pilot's watch itself must not interfere with the avionics such as the aircraft's emergency compass. A further safety aspect is that a pilot's watch must not dazzle the pilot and must be largely free of reflections.


The aim of the project was to draw up a clear catalogue of technical and functional specifications which precisely describe the time measurement requirements during flight in the following categories:

1. Functionality

  • Required functions during flights operating under visual and instrument flight rules
  • Readability in daylight and in darkness
  • Good operability
  • Accuracy and power reserve

2. Resistance to external stress

  • Absolute and cyclical ambient pressure changes
  • Operative temperature range and rapid temperature change
  • Shock and impact resistance, G-forces and vibration
  • Resistance to water and other aviation fluids
  • Effects of magnetic fields on the watch

3. Safety and compatibility with other instruments

  • Effects of the watch's magnetic signature on avionics
  • Avoidance of reflections and dazzle
  • Appropriate form
  • Secure strap fastening
Differential pressure test: The EZM 10 must withstand alternating ambient pressure levels.
A pilot's watch such as the 103 Ti Ar must be able to withstand extreme vibration.
The case gasket of a pilot's watch must be resistant to kerosene.
Shock and impact resistance tests on the EZM 10.
Dynamic G-force test on the 103 Ti Ar.
A pilot's watch such as the EZM 10 must have no magnetic influence on the emergency compass.

Quality seal of TESTAF-certified watches

Based on these requirements the Aachen University of Applied Sciences developed an exacting testing regime which can be used by all watch manufacturers. Pilot's watches which pass the TESTAF conformity tests are awarded a certificate. Only TESTAF-certified watches are permitted to feature the protected quality seal – a stylised silhouette of an aircraft framed in the cockpit display of the attitude indicator. The theoretical findings were confirmed by subjecting them to practical and detailed tests by Airbus Helicopters. These were carried out by chief test pilot Volker Bau (Dipl.-Ing.) over several weeks during the testing of a helicopter prototype. TESTAF can be downloaded free of charge as a scientific publication from www.testaf.org. The site also contains other items of information. A technical committee, of which Sinn Spezialuhren is also a member, was set up to oversee the further development of TESTAF. TESTAF also provides specialist editorial staff with a reliable set of scientifically and practically proven evaluation criteria. The media partner, Uhren-Magazin, has declared its express support for the project.

Presentation of TESTAF by Prof. Dr.-Ing Frank Janser at Airbus Helicopters in Donauwörth on 19 July 2012.

Positive public response

On 19 July 2012 Sinn Spezialuhren, the Aachen University of Applied Sciences and Airbus Helicopters presented the first version of TESTAF at the German headquarters of Airbus Helicopters in Donauwörth. The research results were welcomed by the representatives of various watch manufacturers, the aviation industry and the specialist press.