At steady state, operation of both the chemostat and turbidostat are identical.
It is only when classical chemostat assumptions are violated (for instance, out of equilibrium; or the cells are mutating) that a turbidostat is functionally different.
[3] While most turbidostats use a spectrophotometer/turbidimeter to measure the optical density for control purposes, there exist other methods, such as dielectric permittivity.
[4] The morbidostat is a similar device built to study the evolution of antimicrobial resistance.
The aim is also to maintain constant turbidity levels, but this is controlled using the addition of antimicrobials.