- IIoT-capable with LPWAN transmission
- High transmission range for the measured values (up to 10 km [6.2 mi]) with long battery life (up to 10 years)
- Battery-operated or external power supply for radio transmission possible
- Easy integration thanks to several radio standards
 Datasheet |
| User Manual |
- IIoT-capable with LoRaWAN® transmission
- Battery-operated LoRaWAN® wireless transmission based on LPWAN technology
- High transmission range for the measured values (up to 10 km [6 mi]) with long battery life (up to 10 years)
- Two intrinsically safe analogue input signals with 4 ... 20 mA
- The determination of differential pressures is possible
| Datasheet |
| User Manual |
- IIoT-capable with LoRaWAN® transmission
- Battery-operated LoRa® radio transmission based on LPWAN technology
- High transmission range for the measured values (up to 10 km) with long battery life (up to 10 years)
- Exchange of the radio unit possible in ATEX zones
| Datasheet |
| User Manual |
- IIoT-capable measuring instrument in combination with WIKA radio unit, model NETRIS®3
- Process- and procedure-specific solutions possible
- Operating limits:
- Process temperature:T = -80 ... +200 °C [-112 ... +842 °F]
- Operating pressure: P = vacuum to 80 bar [1,160 psi]
- Limit density: ρ ≥ 400 kg/m3
- Wide variety of different process connections and materials
- Intrinsically safe version Ex i
| Datasheet |
IIoT Level Monitoring – from Tank to Dashboard
IIoT level monitoring connects radar, ultrasonic, hydrostatic and differential-pressure measurements as well as limit switches via RS-485/Modbus RTU, HART (4–20 mA), IO-Link, or Ethernet. An edge gateway collects, scales, and timestamps data, sends it securely via MQTT/HTTPS to SCADA/cloud, and enables real-time dashboards, alarms, reporting, and traceability — vendor-agnostic integration. With TLS/VPN, role models, and audit logs, you meet security and compliance requirements. This turns tanks and vessels into transparent, maintenance-friendly IIoT assets that improve supply reliability and reduce costs.
FAQ on IIoT Level Monitoring
Answers to common questions about measurement principles, protocols, parameterization, data models, security, hazardous areas, and practical tips for tanks, silos, and pits.
Are all RS-485/Modbus devices automatically IoT-ready?
No. RS-485 is field communication. It becomes IoT only with an edge/gateway (Modbus→MQTT/HTTPS), stable IDs, secure transport (TLS/VPN), and alarm/telemetry logic.
Which level measurement principles are common and when to use them?
| Principle | Medium | Advantages | Consider |
|---|---|---|---|
| Radar / GWR | Liquids/solids | Insensitive to steam/temperature | Blocking distance, internals |
| Ultrasonic | Liquids | Cost-effective | Foam/turbulence, temperature |
| Hydrostatic | Liquids | Simple, robust | Density/temperature compensation |
| Δp (differential pressure) | Liquids | Closed tanks | Density, venting, impulse lines |
| Capacitive/point level switch | Liquids/solids | Simple alarm | Build-up, calibration |
Which protocols work together?
Field: Modbus RTU (RS-485), HART (4–20 mA), IO-Link. Toward IT/cloud: MQTT or HTTPS/REST. This separation ensures robust field polling and efficient upstream telemetry.
How do I convert raw values (distance/pressure) to level/volume?
Via linearization: distance→level (geometry/offset), pressure→level (ρ·g), optional temperature/density compensation. Volume via strapping table or shape-specific formula.
What is a strapping table and what does it look like?
| Level (mm) | Volume (L) |
|---|---|
| 0 | 0 |
| 250 | 1,250 |
| 500 | 2,650 |
| 750 | 4,100 |
| 1,000 | 5,600 |
Strapping tables are stored at the edge; interpolation provides volume/capacity for alarms and planning.
Which polling/publish intervals make sense?
| Use case | Interval | Note |
|---|---|---|
| Storage tank (calm) | 10–60 s | On-change (Δ≥0.5%) saves traffic |
| Process tank | 2–10 s | Thresholds with hysteresis |
| Shaft/overflow | 1–5 s | Fast alarms/events |
| Silo (bulk solids) | 10–30 s | Filter dust/turbulence |
How should I design an MQTT topic scheme for level?
Example: site/{plant}/tank/{id}/level/value, .../percent, .../volume, .../status, .../alarm. Publish metadata (unit, density, geometry, strapping version) as retained properties.
How do I secure communication and access?
TLS (MQTTS/HTTPS), per-gateway certificates, VPN/zero-trust, roles/scopes, API keys/certificates, audit logs, signed firmware, and regular patch/certificate management.
Which installation tips are critical?
Clear line of sight (radar/ultrasonic), away from inlets/agitators, respect blocking distance, correct venting (Δp), vibration decoupling, and clean cable/EMC layout (RS-485).
How do I handle foam, condensation, and turbulence?
Use stilling/guide pipes (radar/GWR), mean/median filtering, damping/tracking, move the measuring point, or switch from ultrasonic to radar if needed.
How do I set tank-level thresholds and alarms?
Hi/HiHi/Lo/LoLo with hysteresis/deadband, rate-of-change, minimum fill time after start, pump interlocks. Trigger alarms locally at the edge (cloud-independent).
How do I calculate fill percentage correctly?
% = (level − zero) / (span) × 100. For non-linear tanks, derive percent from volume (strapping), not from height.
What power supply is typical?
| Component | Supply | Note |
|---|---|---|
| RS-485 sensor/transmitter | 12–30 V DC | Correct termination/biasing |
| HART (4–20 mA) | 24 V loop power | Communication resistor as required |
| Edge gateway | 24 V DC / PoE | UPS/buffer, watchdog |
| Wireless node (LoRa/LTE) | 12/24 V or battery | Interval ↔ battery life |
How do I integrate existing 4–20 mA level instruments?
Via edge analog inputs (optional HART modem). The edge performs scaling/linearization and publishes values via MQTT/HTTPS with timestamp/quality flag.
What belongs in the historian/reporting?
Level, %, volume, alarms/acknowledgements, pump starts, fill/drain rates, sensor status, maintenance/calibration; keep time base (UTC) and units consistent.
How do I account for density/temperature effects with hydrostatic/Δp?
Measure density and temperature or set them as properties; the edge corrects pressure→height dynamically. Version strapping/density profiles for media changes.
Does this work in hazardous areas (ATEX/IECEx)?
Yes, with suitable Ex approvals and intrinsically safe barriers/isolators. Place gateways in safe zones where possible; provide full documentation for explosion protection.
How can I proof-test thresholds without emptying the tank?
Edge simulation mode (virtual levels), HART/Modbus current/distance simulation, bypass via safe test routines, and log results (audit log).
What are rough cost ranges?
| Scope | Deliverables | Effort (estimate) |
|---|---|---|
| ≤ 10 measuring points | Edge, wiring, basic dashboard | 1–3 person-days |
| 10–50 | Segments, alarms, roles | 3–10 person-days |
| 50+ | Fleet mgmt, templates, reporting | PoC → phased roll-out |
How do I start a pilot effectively?
Workshop (tank list, media, goals/KPIs) → edge + 3–5 tanks → mapping/topics/strapping → dashboards/alarms → security baseline → acceptance & ROI review → roll-out plan.
Which KPIs are useful for level?
Service level (% time in target band), fill/drain duration, number of over-/underfills, forecast remaining time, pump starts per day, leakage indicators (night-time drop).