The phrase "a certain number of tests" is correct and usable in written English.
It can be used when referring to an unspecified quantity of tests, often in a context where the exact number is not important or is unknown.
Example: "The researchers conducted a certain number of tests to validate their hypothesis."
Alternatives: "a specific quantity of tests" or "an unspecified number of tests".
When the bonding layer for the DLC coating case was Si-based, it could not prevent crack propagation into the substrate after a certain number of test cycles.
You can only have a certain number of missed tests within a set period.
A certain number of experimental tests on FRP reinforced concrete elements carried out up to collapse are numerically reproduced and the related predictions, in terms of peak loads and failure modes, are critically discussed.
However, it must be noted that there are provisions in place that allow reinstatement of education benefits after evidence of drug rehabilitation and a certain number of clean drug tests.
GJH is defined from a certain number of joint mobility tests [ 2] and is part of the diagnostic criteria for benign joint hypermobility syndrome (BJHS) [ 3], defined for adults, and for a number of serious hereditary connective tissue diseases, like Ehlers-Danlos Syndrome (EDS) and mild types of Osteogenesis Imperfecta.
Rather, he said, they had each logged a certain number of hours as test pilots for the Navy and the next step seemed inevitable.
Once Morwilog is built, we need a dataset accomplishing a certain number of characteristics for testing the system: Firstly, the feedback provided by the operator has to be simulated during the experiments.
Generalized joint hypermobility (GJH) is one of the musculoskeletal disorders, and is defined by a certain number of positive joint mobility tests [ 3].
It is found that, given a certain number of site-specific pile load tests, the effect of updating depends on the mean and the COV of the measured model bias factor.
A certain number of locations are selected to test this method.
