"essential measures" is a correct phrase and can be used in written English.
It is often used to refer to necessary actions or steps that need to be taken in order to achieve a specific goal or address a problem. Example: The government has implemented essential measures to control the spread of the virus, including a nationwide lockdown and mandatory mask-wearing in public places.
Fertility rates are essential measures of a society's demographic balance.
Concerning the computational procedure, essential measures were taken to optimize convergence and computing time.
Congress commissioned the development of objective employment data, and, since the nineteen-forties, two government data sets have been essential measures of the nation's economic health.
Both surveillance drones and anti-poaching dogs are not only imaginative but essential measures to prevent the elephants in Mkomazi Park being killed for their ivory.
They could be used to illustrate the structure and distinctive features of insect anatomy, insect domestication, retrogressive mutations, and the essential measures which are taken by breeders to monitor productivity and selection, including extermination to preempt racial degeneration.
But Yang Fengchun, of Peking University's School of Government, told the Associated Press news agency: "Although after SARS the government promised a more open media environment and to protect people's right of expression, without essential measures it's just empty talk.
Establishing energy efficiency standards is an essential measure to cope with these challenges.
Therefore, materials characteristics are essential measure for evaluating PR of a nuclear energy system.
Uncertainty in this context is an essential measure of quality for stakeholder and decision makers.
The report criticizes the Bloomberg administration, saying it failed to deliver on what the mayor has repeatedly endorsed as an essential measure of public accountability: progress evaluations.
But enacting it would provide an essential measure of legal protection, and send an important message of tolerance -- one that is terribly overdue.
