The phrase "alert signal" is correct and usable in written English.
It can be used in contexts where a warning or notification is being communicated, often in technical or safety-related discussions.
Example: "The system will emit an alert signal if any unauthorized access is detected."
Alternatives: "warning signal" or "notification signal".
This evolutionary process is demonstrated by the predator alert signal of Thomson's gazelles (Gazella thomsoni).
We could also consider a missile … If the crew didn't send an alert signal, it's because what happened was very sudden.
I can faithfully report that the Police Department's newest and soon-to-be-ubiquitous emergency alert signal does not cause eyeglasses to sprout hairline cracks that branch out across the lens and hang there for one long moment before the entire thing shatters with a delicate "plink," as in some Bugs Bunny cartoon.
(Spoiler alert: Signal is the safest choice).
The system then sends an alert signal that is picked up on the ground".
Any major deviations prompt an alert signal, with specific recommendations for the farmer on how to respond.
Vague color-coded alert signals flicker in and out of consciousness.
Hennessy enlisted 1,200 volunteers; the fire alarm bells have been stepped up in volume & will serve as alert signals.
This type of wireless device also sends out alert signals to the physician when the patient's heart rate becomes abnormal.
Although the state provides 6percentt of the financing for the system, an executive said it might reduce emergency and Amber Alert signals, drop some local programs and reduce educational programming.
As G.I.'s continue to fight and die in Iraq, the national leaders who put them needlessly in harm's way are now flashing orange alert signals to convey that Al Qaeda -- the enemy that should have been in our sights all along -- is poised to strike us again.
