The phrase "a certain sample" is correct and usable in written English.
It can be used when referring to a specific but unspecified sample in a context, such as research or analysis.
Example: "In our study, we collected data from a certain sample of participants to ensure diverse representation."
Alternatives: "a specific sample" or "a particular sample".
As air flows through the tube, mercury sticks to the gold, enabling researchers to determine the concentration in a certain sample of air.
The machine uses X-ray attenuation, meaning it analyzes the amount of X-rays that get blocked by the material to infer how much of the material is in a certain sample.
Each line represents a certain sample size (i.e. seven per cluster).
The objective of 'nontargeted' metabolic profiling analysis is to detect as many metabolites as possible in a certain sample.
However, sometimes it is not possible to maintain a certain sample size along the experimental design, especially in field studies.
As the radius is shorten, when unknown samples are recognized, the probability that an uncertain sample is recognized as a certain sample is reduced.
To describe spatial patterns in the field, several observations are made according to a certain sampling design.
The Navier-Stokes and convection diffusion equations are solved in two dimensions and the concentration profile is obtained after a certain sampling period.
However, speech features depend on the sampling rate of the speech and subsequently acoustic models built using features extracted at a certain sampling rate cannot be used by a speech engine to recognize speech sampled at a different sampling rate.
The measured quantity is the distance estimate between the sensor nodes at a certain sampling rate (500 ms in our case).
The sample households were drawn from each administrative unit from the list of names after a certain sampling interval (K) that was determined by dividing the total number of households by the predetermined sample size of each kebele.
