Digitize legacy tank gauges without replacing them
Hall-effect retrofit sensing that converts mechanical gauge movement into structured digital level data.
Built for distributors managing tanks in the field.
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Retrofit Sensing for Mechanical Tank Gauges
Hall Pro is a Hall-effect sensor that attaches to existing Rochester analog gauges via cable — without replacing the gauge. It reads the needle position magnetically and transmits fill level data to FoxPortal. The Rochester analog gauge face remains in place as the physical on-site level indicator.
Designed for active tank operations — filling, collection, and field service visits where operators need on-site gauge visibility. Certified for Zone 0 explosive atmospheres (SGS22ATEX0060X / IECEx BAS 22.0034X / II 1 G Ex ia IIC T4 Ga). Compatible with Rochester Junior, Senior, and 4″/8″ gauge formats.
Where Hall Pro Fits
- Active LPG tank filling and collection operations requiring on-site level visibility during service
- Field technicians and delivery drivers who need real-time gauge readout during operations
- LPG fleets with 4″ or 8″ gauge formats — not supported by FoxHall
- ATEX Zone 0 installations requiring intrinsically safe certified hardware (II 1 G Ex ia IIC T4 Ga)
- Sites where the existing analog gauge must be preserved — Hall Pro reads it without replacement
Industry applications: LPG
Key Capabilities
- Attaches to existing Rochester analog gauge via cable — gauge remains in place
- Reads gauge needle position via Hall-effect magnetic sensing
- The Rochester analog gauge face serves as the physical on-site level indicator
- Measurement cycle: every 15 minutes — stored hourly, transmitted daily
- ATEX Zone 0 certified: SGS22ATEX0060X / IECEx BAS 22.0034X / II 1 G Ex ia IIC T4 Ga
- Gauge compatibility: Rochester Junior, Senior, 4″, and 8″ formats
- Connectivity: LTE CAT-M1, NB-IoT
- Battery: up to 10 years at 1 transmission/day
Technical Specifications
- Measurement
- Hall-effect magnetic sensing (gauge needle position)
- Range
- 0–99%
- Accuracy
- ±2%
- Display
- Rochester analog gauge face (physical on-site indicator — no digital display added)
- Measurement cycle
- Every 15 min — stored hourly, transmitted daily (instant transmission on fill / leak / large withdrawal)
- Connectivity
- LTE CAT-M1, NB-IoT
- Battery
- Up to 10 years at 1 transmission/day
- Power source
- 3.6 V Lithium-Thionyl-Chloride battery (replaceable)
- Operating temperature
- −30°C to +55°C
- Protection
- IP68
- ATEX / IECEx
- Zone 0 / SGS22ATEX0060X / IECEx BAS 22.0034X / II 1 G Ex ia IIC T4 Ga
- Gauge compatibility
- Rochester Junior, Senior, 4″, 8″
- Mounting
- Attaches to existing Rochester analog gauge via cable
Ideal Use Cases
- LPG distributors running active filling and collection operations with field staff on-site
- Sites with 4″ or 8″ Rochester gauge formats requiring remote monitoring with on-site readout
- Mixed fleets: Hall Pro for high-interaction tanks, FoxHall for passive monitoring sites
- Operations in ATEX Zone 0 environments requiring certified intrinsically safe hardware
Limitations
- Requires a compatible Rochester gauge — not suitable for worn, damaged, or non-standard gauges
- Measurement accuracy (±2%) depends on the quality and condition of the underlying gauge
- Battery life may be significantly reduced in very high-frequency operational use
- For passive remote-only monitoring without active on-site operations, FoxHall is more suitable
When to Use a Different Sensor
Hall Pro is designed for active operations on Rochester gauges with Zone 0 ATEX requirements. Consider an alternative when:
- Passive remote monitoring is sufficient — no active on-site operations required (→ use FoxHall)
- The installation does not require Zone 0 ATEX certification (→ use FoxHall)
- The tank does not have a compatible Rochester gauge — use a direct sensing approach (→ use FoxRadar Gen 4 or FoxPressure Gen 4)
Role Within the FoxInsights System
Hall Pro converts analog gauge movement into digital level data. Monitoring is sensing; forecasting remains platform-layer.