The phrase "ascertain level" is correct and usable in written English.
It can be used when you want to determine or find out the degree or extent of something.
Example: "To improve our services, we need to ascertain the level of customer satisfaction through surveys."
Alternatives: "determine the extent" or "evaluate the degree".
A four point Likert-type scale were used to ascertain level of the practices (from 1 to 4, 1 = always, 2 = often, 3 = sometimes, 4 = never).
A five point Likert-type scale were used to ascertain level of agreement or disagreement for the questions (from 1 to 5, 1 = strongly disagree, 2 = disagree, 3 = uncertain, 4 = agree, 5 = strongly agree).
"Use of Lot Quality Assurance Sampling to Ascertain Levels of Drug Resistant Tuberculosis in Western Kenya". PLoS ONE 11 (5): e0114112.
The academic study, commissioned by the Guardian, involved close analysis of the speeches of leaders who have served 40 countries to ascertain levels of populist discourse.
Visiting a pharmacy can feel shameful or intimidating with a barrage of questions asked to ascertain levels of responsibility, known as the "Gillick" competency.
All the thin films were characterized using multiple advanced techniques to accurately ascertain levels of contamination as well as to determine their exact surface density.
Molecules are laid directly on top of gold electrodes, and current flowing across these circuits is plotted on a graph to ascertain levels of conductivity.
Immunohistochemical analysis was performed to ascertain levels of Lkb1 in lesions and tumors from Pdx1-Cre, Kras G12D/+ (KC), and Pdx1-Cre, Kras G12D/+, Lkb1 flox/+ (KLC) mice.
The alcohol use measure asks three questions to ascertain levels of current drinking and may not capture the entirety of drinking consumption over the four-month period between assessments.
We present the first study to ascertain levels of drug resistant tuberculosis since the adoption of multi drug short course therapy and establishment of a DOTS program in 1992 [ 16].
The survey's purpose was to ascertain levels of actual and desired public involvement in the remediation process; to identify health, environmental, economic, and future land-use concerns associated with the site; and to solicit remediation strategy preferences.
