The parameter at a glance.
SSVI is a stirred settlement result. It is available only when the S3A is used with the optional stirrer module.
mL/g
Unit or result
30 minutes
Test timing
Optional stirrer required
S3A scope
Understanding Stirred Sludge Volume Index (SSVI).
SSVI is a stirred settlement result. It is available only when the S3A is used with the optional stirrer module.
Optional module
The standard S3A does not provide SSVI without the optional stirrer. Specify the module where the site procedure requires a stirred test.
Keep methods distinct
SVI and SSVI are different test methods. Compare like-for-like results when reviewing historical or multi-site data.
Completed result storage
The stirred result is stored after the test has completed, with date, time and sample-location information.
One sample. A complete settlement picture.
The S3A measures MLSS rapidly, then continues the unattended 30-minute settlement test for SVI, SSL, supernatant clarity and floating sludge. The optional stirrer is required for SSVI and SSSL.
01 / MLSS
Rapid MLSS measurement
A result in approximately 10 seconds from a compact 210 ml sample, within the specified 50 to 6,500 mg/L range.
02 / Settlement test
Unattended settlement analysis
The analyser continues the 30-minute cycle and stores the completed result after the test has finished.
Optional stirrer for SSVI and SSSL.
The separate optional stirrer enables SSVI and stirred settled sludge level. Its cable connects to the round four-pin socket at the rear of the S3A; this is not the green six-pin MODBUS connector.
During the 30-minute stirred test, stirring stops approximately five minutes before completion to let the sludge level out. Follow the operating manual and do not manually rotate the stirrer blade.
Explore related S3A parameters.
See how the S3A measurements work together within one repeatable settlement-analysis workflow.
SVI
Relate settled sludge volume to MLSS concentration after the 30-minute settlement test.
SSSL
Measure stirred settled sludge level when the optional stirrer module is fitted.
MLSS
Measure mixed liquor suspended solids from a compact 210 ml sample in approximately 10 seconds.