The phrase "at long intervals" is correct and usable in written English.
It can be used to describe actions or events that occur infrequently or with significant time gaps between them.
Example: "The train arrives at long intervals, making it difficult for commuters to plan their journeys."
Alternatives: "after long periods" or "at infrequent times".
Hanwell Snr came to Hanwell like a comet, at long intervals.
Thereafter, instead of appearing in completely reset editions at long intervals, the encyclopaedia was reprinted annually.
At long intervals we chirp feebly to each other, then sleep and dream sad dreams".
When the environment is warm, they contract at long intervals, providing a free flow of blood.
Residential buildings are fairly static in their function, changing only at long intervals.
"If I had more ideas, I would write them, but unfortunately they only come at long intervals.
Well, the problem of embedded inflation applies only to prices that are set at fairly long intervals — especially to wages, which are usually set only once a year.
Imagine that there are two entrepreneurs, Harry and Louise, both of whom change prices only at fairly long intervals — say, once a year.
If the plasma half-life (t1/2)—the time it takes for the plasma concentration to fall to 50 percent of its starting value is long, doses can be given at relatively long intervals (e.g., once per day), but if the t1/2 is short (less than about 24 hours), more frequent doses will be necessary.
What is likely to happen if we make contact with ETI? Given the size of astronomical distances and assuming the speed of light as the maximum possible velocity, the most likely outcome is not real contact but merely an exchange of messages, perhaps at very long intervals.
In Figures 4 and 5 we examined a single re-exposure at increasingly long intervals from initial infection (re-exposure scenario 2).
