The phrase "a critical level of" is correct and usable in written English.
It can be used when discussing thresholds or important degrees of something, often in scientific, technical, or analytical contexts.
Example: "The experiment requires a critical level of temperature to ensure accurate results."
Alternatives: "an essential degree of" or "a vital amount of".
It turns out that there is a critical level of manoeuvrability.
Neuronal firing and early network oscillations were induced after a critical level of light intensity was reached.
During the day, the index slipped below 944.75, the intraday low hit on Sept. 21 after the Sept. 11 attacks and a critical level of technical support.
You: It's okay I've got this: when it hits a critical level of damage, the robot transforms into something else for one last onslaught?
A critical level of air relative humidity was required to generate porous particles for each tested formulation.
An equation for determination of a critical level of degradation corresponding to the offset of fracture is constructed.
A critical level of membrane hydration is required for ignition; insufficient membrane hydration will extinguish the fuel cell current.
Similarly, male emperor penguins that incubate eggs in anticipation of the female's return only reach a critical level of hunger depletion when their partner is expected back.
An analytical method has been developed to predict creep crack initiation (CCI), based on the accumulation of a critical level of damage at a critical distance.
He warned that if the carbon emissions of China and India continue to grow at the same pace as their economies, mankind would be unable to prevent a critical level of warming.
This revealed anomalous behaviour: entanglement slippage was found to arrest spontaneously at a critical level of orientation, associated with the first appearance of crystallinity in the drawn specimens.
