inter range instrumentation group (IRIG)
Electronic systems such as for communication, measurement technology, telemetry or data processing require information about the exact time of acquisition, the exact time of day and the date for the reconciliation of the data. This information is provided by time codes, which are recorded together with the data.
There are various time codes especially for video, for video recording, electronic editing, crossfading, etc. The IRIG (Inter Range Instrumentation Group) time code, on the other hand, is used in metrology, in data loggers, and in measurement and data processing systems. It dates back to the middle of the last century and has been adapted to the needs of modern measurement technology in the meantime. From the individual IRIG documents one recognizes the update. Thus the original document has the designation 104-60 and dates from 1960, the last version 200-04 is from 2004.
The IRIG time code consists of a letter followed by three digits, each digit being assigned a property. The letter represents the number of synchronization pulses. These can range from 1 pulse per minute( PPM) to 10,000 pulses per second( PPS). The first digit identifies the signal type, the second the resolution of the carrier signal and the third the code.
A typical application for the IRIG time code is earthquake research, where measurement data must be acquired at a wide variety of locations and synchronized in time. Only in this way can the propagation of the earthquake be precisely traced.