APTA RT-SC-S-009-03
Audio Frequency Track Circuit Inspection and Maintenance
Abstract
This standard offers requirements necessary to ensure the safety and reliability of audio frequency track circuit systems.
Keywords: AF track circuit, audio frequency track circuit, bond, HF track circuit, impedance bond, shunt, shunting device, signal, track circuit
Summary
This standard provides audio frequency track circuit tests that verify train detection (shunting), and continued proper operation. These tests include recording the measured values for comparison over time to reveal trends in transmit and receive signal levels, which can help predict possible equipment and/or track deterioration. This standard also provides track circuit inspection requirements.
Document History
| Document Number | Version | Publication Date | Publication | Related Information |
|---|---|---|---|---|
| APTA RT-SC-S-009-03 | Rev. 2 | 01/31/2025 | Published | Current |
| APTA RT-SC-S-009-03 | Rev. 1 | 12/31/2014 | Published | Superseded |
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