Race timing glossary: essential terms from decoder to photo finish, explained simply

Race timing has its own jargon. Here is an alphabetical glossary of its most important terms.

Terms A to F

• Active transponder: a battery-powered chip that transmits its own signal. It has a longer range, is larger and more expensive, and is used mainly in motorsport.
• Antenna: the part of the reader that creates a radio field and receives responses from chips.
• Gun time: time measured from the starting signal, regardless of when the competitor crosses the start line.
• Net time, chip time: time from crossing the start line to the finish.
• Read zone: the area in front of the antenna in which the reader detects a chip.
• Decoder: a device that receives transponder signals and records the code and time.
• DNF, DNS, DSQ: Did Not Finish, Did Not Start, disqualified.
• Photocell: a light beam that records the moment it is broken.
• Photo finish: a camera at the finish line that records a narrow strip of the image and combines the strips into a picture with a time axis; learn more in Photo finishes in horse racing.

Terms G to P

• Mass, wave, and individual starts: different ways for competitors to begin a race; learn more in Types of race starts.
• Checkpoint: a point on the course where a passing time or split time is recorded.
• Cut-off: the latest time by which a competitor may reach a given point; learn more in Time limits at sporting events.
• Split time: the time recorded at a checkpoint during a race.
• NFC chip: a chip with a range of a few centimeters that is held close to a phone.
• Offline mode: an app’s ability to record and store data without an internet connection and upload it later.
• On-metal chip: an RFID chip designed to work reliably on a metal surface.
• Passive chip: a chip without a battery that draws energy from the reader’s signal.
• Fully automatic timing (FAT): timing without human intervention, required in athletics for records in track races up to 800 meters, for example.
• Event regulations: a document containing the event rules, which should also state the timing method and how ties will be resolved.

Terms R to Z

• RFID: identification using radio waves. The UHF band in Europe is 865 to 868 MHz; learn more in How an RFID chip works in running.
• Timing mat: a mat with built-in antennas that competitors cross.
• Start list: a list of competitors with their numbers, categories, and start times.
• Bib number: the number worn on a competitor’s chest, often with an integrated chip.
• Clock synchronization: aligning the time across devices; learn more in Clock synchronization in race timing.
• Transponder: a device that responds with a unique code detected by a reader.
• Backup timing: an independent second timing method used in case of failure; learn more in Backup timing.

Terms used in TAQIO

In the TAQIO app, you will encounter terms such as start list, checkpoint, split time, start type, and passing-record method—tap, QR, NFC, or RFID. You can find an explanation in TAQIO: race timing on your phone.