Passive Marker Locating for Reliable Asset Identification
Passive markers (EMS/RFID) let you permanently tag utilities and fittings for fast rediscovery. Dedicated receivers detect each marker type clearly—even under backfill—supporting documentation, fault response and as-built verification.
- Rapid pinpointing of key points (branches, joints, valves)
- Multiple form factors (e.g., ball, disk, low-profile)
- Utility-specific marker frequencies for clear attribution
- Optional RFID memory for IDs, depth and notes
- Rugged designs for buried and wet environments
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What is a passive marker?
Passive markers are maintenance-free tags with a distinctive field pattern detectable from the surface. A compatible receiver identifies the pattern and enables precise point locating—no injected signal required.
Marker types & use cases
- Ball markers: self-orienting, suitable for varied depths
- Disk/low-profile markers: compact form for shallow cover
- RFID markers: writable memory for IDs, depth or notes
Selection guide
- Application: point features (joints, tees) vs. corridor indication
- Depth: match marker form factor and receiver range to cover
- Utility mapping: choose the utility-specific marker frequency
- Data needs: pick RFID when on-marker data storage is required
Pro tips
- Install with correct orientation and record burial depth
- Capture marker positions in GIS, including serial/ID (for RFID)
- Verify locate before backfilling
FAQ
- How do markers differ from sondes?
- Markers are passive, permanent tags for points; sondes are active transmitters for temporary tracing tasks.
- Do I need a special receiver?
- Yes. The receiver must support the specific marker frequency and, for RFID, read/write data.
- How deep can markers be located?
- Range depends on marker size, soil conditions and receiver. Larger markers are typically detectable at greater depths.
- Can I edit data later?
- With RFID markers, compatible devices can write and read IDs, depths and notes after installation.
The right mix of marker form factor and receiver capability ensures fast, reliable rediscovery of buried assets.