The same process question. Different workflows.
Both approaches help operators review how activated sludge separates during a defined test. The practical difference is how the sample is measured, the cycle is managed and the completed results are recorded.
Sampling
Representative in both methods
Timing
A defined 30-minute test
Records
Comparable completed results
What changes when testing is automated?
Automation can take over the measurement cycle, but it cannot make an unrepresentative sample useful. Keep the sampling point, preparation and test method consistent whichever approach you use.
Manual observations
In a manual test, an operator times settlement in a graduated vessel, reads the settled volume and records observations. Calculating SVI also requires an MLSS result for the sample and consistent use of units.
Automated measurements
The S3A measures MLSS from a 210 ml sample in approximately 10 seconds, then completes the 30-minute settlement cycle unattended. The completed test includes SVI, SSL, supernatant clarity and floating sludge.
Comparable records
Manual records need the location, time, method and results recorded consistently. The S3A stores completed results with date, time and location information, for up to 28 results at each of three locations.
Compare the work around the test.
The strongest case for automation comes from the routine on your site: how often tests are run, how easily operators can return at the correct time, and how consistently results are recorded and reviewed.
01 / Manual workflow
Operator-managed timing
A manual test remains useful where the site can maintain consistent preparation, timing and recording. Include the time needed to obtain MLSS, calculate SVI and transfer results into the site record.
02 / S3A workflow
Unattended settlement
After starting the S3A test, the operator can continue with other work while the 30-minute cycle runs. Sampling, preparation, routine care and interpretation still need an agreed operating procedure.
Keep the method and limitations clear.
SVI and stirred SSVI are different methods. The S3A requires its optional stirrer for SSVI and SSSL. Do not combine stirred and unstirred results into one trend without identifying the method.
Neither workflow diagnoses the cause of poor settlement on its own. Review the result with wider process information. The S3A is not a continuous online analyser or a substitute for final-effluent compliance testing.
Choose your next step.
Read the test background, explore the individual measurements or use the buyer checklist to decide what your treatment works needs from an analyser.
Understand the test
Read the existing guide to the 30-minute settlement test and how its measurements fit together.
Explore the measurements
Review what each S3A result represents and which measurements need the optional stirrer.
Specify an analyser
Use the buyer guide to check measurement range, test method, sample handling and result storage.