01
Conventional activated-sludge treatment
Routine analysis of MLSS and settlement behaviour helps operators build a clearer picture of upstream biological-process stability. The unattended test supports a repeatable routine.
02
Sequencing batch reactors
The S3A supports routine comparison of MLSS, SVI, settled sludge level and supernatant clarity where the sample falls within the instrument specification.
03
Membrane bioreactors
The S3A can support routine activated-sludge testing in MBR applications, including MLSS and settlement indicators. It does not monitor membrane condition or fouling.
04
Anammox processes
Activated-sludge monitoring where the representative sample and MLSS concentration fall within the stated 50 to 6,500 mg/L range.
05
Wastewater treatment laboratories
Compact routine testing where consistent procedures and completed-result comparison are valuable.
06
Operational site testing
Repeatable settlement testing close to the process, using a compact sample and a simple push-button interface.
A consistent way to compare samples.
Good field data starts with a safe, representative sampling point and a consistent operating technique. The following workflow helps make routine checks comparable.
01.
Collect
Collect a representative mixed-liquor sample from the process point selected by the operator. Return to the same sampling point whenever possible so that changes reflect the process rather than the location.
02.
Prepare
Prepare the 210 ml sample using a consistent sampling method and the site’s operating procedure.
03.
Load
Fill the S3A sample tube and place it in the analyser. Operate indoors in a safe area, away from direct and reflected sunlight.
04.
Start
Start the analysis. The S3A runs the MLSS check and the 30-minute settlement cycle without continuous operator attention.
05.
Review
Review the completed MLSS and settlement outputs alongside the sample identity and site observations.
06.
Store
Store the completed result against the selected location. The unit retains 28 results for each of three locations, with date and time.
Technical specifications.
Core S3A information for specification and application review.
| MLSS range | 50–6,500 mg/L; above 6,500 mg/L is indicated as INF |
|---|---|
| MLSS result | Approximately 10 seconds |
| Settlement cycle | 30 minutes |
| Sample volume | 210 ml |
| Measured parameters | MLSS, SSL, SVI, supernatant clarity and floating sludge |
| Optional stirrer | SSVI and SSSL |
| Data storage | 28 results for each of three locations |
| Calibration | Known site-specific MLSS sample of 2,000–4,000 mg/L; repeat after large sludge changes |
| Optional connectivity | MODBUS RTU, two-wire RS-485; read functions 03/04. Write function 06 is limited to Holding Register 40001 (slave ID, 1–247); it does not write measurement values or control tests. Specify when ordering; client integration required. |
| Operating environment | Indoor, safe area; 0–45°C, noncondensing. Keep out of direct and reflected sunlight. |
Specifications are based on the current PMA S3A brochure and may be subject to product development. Confirm critical requirements with PMA before specification.
What the readings tell you.
S3A measurements give operators a repeatable view of mixed liquor and settling behaviour. Used as part of a routine monitoring programme, they help reveal process changes over time. Follow the activated-sludge monitoring guide for the complete sample-to-result route. Continue with the industrial effluent, food and beverage, distillery and brewery application pages.
Where S3A fits
Compare sample-based MLSS and settlement results with process observations. The S3A is not an in-tank blanket-depth or continuous online monitor.
Activated-sludge monitoring
See how MLSS and sludge-settlement measurements support routine activated-sludge monitoring with the portable S3A workflow.
Explore applicationIndustrial effluent
See where the S3A supports MLSS and sludge-settlement checks in industrial activated-sludge treatment, and what to confirm before use.
Explore applicationFood and beverage wastewater
Explore S3A MLSS and settlement monitoring for food and beverage wastewater plants with biological treatment, including brewery and distillery routes.
Explore applicationDistillery wastewater
Learn where S3A MLSS, SVI and settlement checks can support distillery wastewater treatment with an activated-sludge stage.
Explore applicationBrewery wastewater
Explore where S3A MLSS, SVI and sludge-settlement checks fit brewery wastewater plants with an activated-sludge treatment stage.
Explore applicationAeration basins
MLSS readings support routine activated-sludge process checks and comparison between lanes or operating periods.
Sequencing batch reactors
Compare MLSS and settlement results through the site’s established SBR sampling routine, with process context recorded alongside each test.
Return activated sludge
Review return-stream concentration and settlement checks within the instrument range, keeping sample identity and operating context with the result.
Operational measurement, not a replacement for required laboratory analysis.
S3A supports operational checks of activated sludge. Compliance sampling, regulatory testing and any required laboratory analysis should still be completed using the procedures that apply to the site.