Product overview and engineering role
The SimtoLink MLSS sludge-concentration sensor is for process-sensing IoT. Ratings on this page support selection, technical clauses in tender documents, and operations spot checks. Measurement and communications run on a dual-core lockstep MCU, so behavior stays predictable across wide temperature, wide supply voltage, and electromagnetic interference. Maintenance is designed in: pluggable terminals, a watchdog and redundant checks on critical chips, and signed firmware with rollback for volume delivery and remote operations.
This model ships with CAN-FD and a standard industrial connector, ready for an existing SCADA, energy-management, or IoT platform. Southbound point-list templates and northbound MQTT and HTTP push examples shorten commissioning. Volume projects can add enclosure silkscreen, harness length, protocol mapping, and a calibration certificate.
Reliability and field fit
Electrical safety and EMC coverage includes the salt-spray and vibration type tests that apply to this probe. Ports are protected against surge and reversed polarity. Reinforced grounding and a partitioned layout reduce ground-loop and common-mode interference. Outdoor or coastal sites can take a higher ingress rating and a corrosion-resistant coating.
Bulk parameter import, threshold policies, and event video or waveform capture are available on models that include them. Configuration and firmware update over the air. Site acceptance is a power-on self-test, time synchronization on the communications link, and a sample spot check. For metering or safety use, SimtoLink helps with a submission to a third-party metrology institute and supplies type-test documents.
Key hardware parameters
Ratings below are for a typical build, for selection and for tender technical clauses. For a wider range, redundant power, or an intrinsically safe version, ask SimtoLink for the hardware specification and the installation and commissioning guide. Order codes in the family can differ slightly; follow the nameplate and the papers shipped with the unit.
| Parameter | Specification | Notes |
|---|---|---|
| Measurement | MLSS / sludge concentration | mg/L or g/L |
| Range | 0～30 g/L (typical) | Extended by order code |
| Accuracy / linearity | ±0.74 %FS (typical) | Compensated over the full temperature range |
| Update interval | ≤1 s (typical) | Configurable |
| Medium temperature | -34～130 ℃ | Probe-dependent |
| Supply | Loop-powered | Surge protection |
| Output | 4～20mA | Isolated |
| Process connection | Flange DN50 | Stainless steel 316L |
| Ingress protection | IP67 | Continuous immersion |
| EMC | GB/T 17626 Level 4 | Industrial sites |
Typical applications
Four common deployments, for solution design and for judging return on investment:
Aeration tanks and oxidation ditches
Live MLSS from the aeration tank works with dissolved oxygen and air-flow control, so sludge does not break up and aeration does not run past what the process needs.
MBR membrane tanks
Mixed-liquor concentration in the membrane tank helps judge fouling rate and wasting interval, so chemical cleans can be spaced further apart.
Return sludge and dewatering
Concentration at the return-sludge pump room and at the thickener or dewatering feed is used to set the recycle ratio and flocculant dose, and to hold cake moisture steady.
SBR and process models
Feed the MLSS sensor into batch control and a digital-twin platform to learn when to waste sludge and to correct the process model.
Installation, grounding, and maintenance
- Check supply range and polarity before energizing. Measure bus voltage and breaker rating with a multimeter if the cabinet drawing is unclear.
- Use shielded twisted pair, ground the shield at one end, and keep the run off long parallel paths with high-power cables.
- Prove bidirectional read and write, and a threshold trip, against the platform in the lab before the probe goes to the basin.
- Outdoor heads need a drain path and ventilation. Recheck the seal face on rounds. Earth resistance for lightning protection has to meet the local code.
- On a running plant, take a sample spot check and archive logs every 24 months.
Ordering, documentation, and support
Hardware specification, outline drawings, a wiring schedule, and example projects are available from SimtoLink. Volume orders can include a sample review and inspection at the factory. Warranty and calibration follow the contract and the documents packed with the probe.