The phrase "at constant levels" is correct and usable in written English.
It can be used in contexts where you want to indicate that something remains unchanged or stable over time, such as in scientific or technical discussions.
Example: "The temperature was maintained at constant levels throughout the experiment to ensure accurate results."
Alternatives: "at stable levels" or "at unchanging levels".
However, these cannot usually be supplied at constant levels.
Substrate temperature and bias voltage were held at constant levels.
This helps cells protect themselves from mutations in individual enhancers and ensures that important genes are transcribed at constant levels, regardless of these mutations.
An experimental facility was designed and operation parameters such as the ultrasonic power, temperature, and gas flow rate were strictly controlled at constant levels.
Melosh's team also found that when they sampled from a group of cells day after day, certain molecules that should be present at constant levels remained the same, indicating that their sampling accurately reflected the cell's interior.
Because air particles tend to flow along isentropic surfaces rather than at constant levels, the life history of air currents can be conveniently followed from day to day by means of isentropic charts.
Keeping the silane gas flow at constant levels between 50 and 150 sccm the ratio of oxygen gas flow to silane was varied from 0 to ~ 170% in order to vary the stoichiometry of the deposited films.
During continuous MBR operation, macroscopic engineering parameters such as total cell concentration and organic removal rate were maintained at constant levels, however, microbial community structure was greatly changed showing a dynamic shift in the dominant bacterial species.
Arnt, the murine homolog of Tango (the heterodimerization partner for Trl) is also expressed in developing lung but at constant levels.
The univariate approach optimizes conditions one-by-one by varying levels of one condition while levels of other conditions are held at constant levels.
The concentrations of NaCl in the soil were maintained at constant levels by watering each pot to weight, as described in the previous section.
