Ultrasonic discharge
Corona, surface discharge and discharge-related emissions around high-voltage assets.
Industry / Railway & Rail Transit
Condition visibility from traction power rooms to tunnels, depots and trackside routes.
HERTZINNO combines acoustic imaging, thermal verification, fixed acoustic monitoring and distributed fiber sensing to help railway teams locate electrical faults, monitor long routes and detect abnormal equipment conditions.
- Traction power
- Switchgear & cables
- Tunnels & routes
- Depots & machinery
- Portable and fixed monitoring
16.7 Hz phase reference is included only for applicable European traction-power systems.
One network, different physical signals
Use the signal that matches the asset and the fault mechanism.
Railway assets combine high-voltage equipment, long cable routes, tunnels, trackside installations and mechanical systems. Electrical discharge may first appear as ultrasonic activity, cable and tunnel risk as a distributed temperature change, route disturbance as vibration along fiber, and machine degradation as a persistent change in operating sound.
Acoustic inspection, thermal verification, DTS and DAS are complementary layers. They should not be presented as interchangeable technologies or as replacements for railway safety procedures and specialist electrical testing.
Temperature change
Heating along power cables, technical corridors, equipment rooms and tunnel routes.
Route vibration
Distributed vibration or disturbance along tunnels, trackside corridors and protected routes.
Abnormal machine sound
Changes around motors, pumps, fans, bearings, gear systems and pneumatic equipment.
01 / Electrical
Traction Power & Electrical Assets
Locate developing electrical faults before they become visible failures.
Portable acoustic imaging helps teams screen traction substations, switchgear, cable terminations, insulators, bushings and selected overhead electrical accessories from an approved inspection position. Thermal imaging can provide a second physical indication when temperature anomalies are also present.
Typical monitoring priorities- Traction transformers and bushings
- Switchgear, disconnectors and bus connections
- Cable terminations and joints
- Selected overhead and trackside electrical assets
02 / Routes
Tunnels & Cable Routes
Monitor temperature and disturbance continuously along the route.
Point sensors can leave gaps across long tunnels and technical corridors. DTS uses optical fiber as a continuous temperature sensor, while DAS uses fiber to detect vibration and acoustic events. The two systems can share route infrastructure but serve different monitoring objectives.
Typical monitoring priorities- Power-cable temperature and hotspot trends
- Tunnel and technical-corridor fire risk
- Distributed vibration and external disturbance
- Route-level event location and alarm zoning
03 / Depots
Depots & Mechanical Systems
Bring acoustic leak and machine-condition inspection into depot maintenance.
Depots and maintenance facilities contain compressed-air systems, motors, pumps, fans, bearings, gear mechanisms and auxiliary equipment. Handheld acoustic imaging supports rapid source localization, while fixed acoustic fingerprint monitoring can track persistent changes at selected critical machines.
Typical monitoring priorities- Compressed-air and pneumatic leakage
- Motors, pumps, fans and cooling equipment
- Bearings, gears and abnormal friction sound
- Repeated faults at selected fixed assets
04 / Trackside
Trackside & Route Infrastructure
Choose fixed monitoring where access is limited or events are intermittent.
Selected substations, electrical rooms, trackside cabinets and protected route sections may require continuous monitoring between inspection rounds. Fixed acoustic cameras provide remote source localization in defined areas, while distributed fiber sensing provides long-route coverage.
Typical monitoring priorities- Critical substations and electrical rooms
- Trackside power and signalling cabinets
- Remote route disturbance and access events
- Video, signal and event evidence for review
16.7Hz
Applicable European traction power
Align PRPD analysis with the actual electrical cycle.
Phase-resolved partial-discharge analysis maps detected pulse activity against the electrical phase. When inspecting an asset that operates at 16.7 Hz, the analysis reference should use 16.7 Hz rather than a conventional 50 Hz or 60 Hz setting.
01
Use the native traction-power phase reference for applicable 16.7 Hz equipment.
02
Store the selected frequency, PRPD pattern, acoustic source map and inspection settings together.
03
Switch to 50 Hz or 60 Hz when inspecting assets that operate at those frequencies.
16.7 Hz is not a universal railway frequency. It is relevant to specific European traction-power networks and should only be used when the inspected asset operates at that frequency.
Inspection and monitoring workflow
Move from wide-area screening to engineering review.
A practical programme begins with the asset and expected fault, then assigns the correct portable, fixed or distributed monitoring layer. Results should remain traceable to the asset, settings, location, time and maintenance action.
Confirm asset and frequency
Record the traction voltage, operating frequency, target component and inspection distance.
Survey the area
Capture audible and ultrasonic signals, temperature or route data according to the monitoring task.
Identify the source or route position
Use acoustic imaging or distributed sensing to map the event to equipment or distance.
Apply the correct analysis layer
Use thermal inspection, PRPD, trend review or a second test method to support engineering judgement.
Preserve maintenance evidence
Store images, signals, settings, risk information, operator notes and follow-up actions.
Product fit
Choose by inspection mobility, signal type and route length.
A railway programme may combine several products. The correct choice depends on the target asset, required evidence, installation conditions and whether monitoring is periodic, fixed or distributed.
HA3
Portable acoustic imaging
Handheld localization of partial-discharge emissions, compressed-air leaks and abnormal machine sound.
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HA3T
Acoustic + thermal inspection
Combine acoustic source localization with 640 × 512 thermal imaging for electrical and mechanical inspection.
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HZ-FA-371
Fixed online acoustic camera
Continuous source localization and platform integration for selected substations, rooms and fixed monitoring zones.
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HZ-DTS
Distributed temperature sensing
Long-distance temperature monitoring for power cables, tunnels and technical routes.
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HZ-iDAS
Distributed acoustic sensing
Route-level vibration and acoustic-event monitoring along optical fiber.
View product →FAQ
Railway monitoring and 16.7 Hz inspection questions.
Why is 16.7 Hz support important?
PRPD analysis uses the electrical phase as its reference. An asset operating at 16.7 Hz should be analysed with a matching 16.7 Hz phase reference.
Is 16.7 Hz used by every railway network?
No. It applies to specific European traction-power systems. Other rail assets may operate at 50 Hz, 60 Hz, DC or another configuration.
Can acoustic inspection be performed on energised assets?
The equipment supports non-contact inspection from an approved position. Railway access rules, electrical safety distances and operator procedures always take priority.
Does acoustic imaging replace electrical testing?
No. It is a screening and localization method that helps teams identify where further testing, maintenance or engineering review may be required.
What is the difference between DTS and DAS?
DTS measures temperature along the fiber route. DAS detects vibration and acoustic events. They use different measurement principles and address different risks.
Can inspection results be retained for comparison?
Images, source maps, PRPD patterns, signals, settings, asset information and maintenance notes can be stored for reporting and historical review.
Plan your railway monitoring programme
Tell us the network frequency, target assets, route length and required inspection workflow.
Share the traction voltage and frequency, target substations or routes, working distance, environmental noise, available fiber, access conditions, reporting requirements and whether the project needs portable, fixed or distributed monitoring.