The phrase "a key barometer" is correct and usable in written English.
It can be used to describe an important indicator or measure of a particular situation or trend.
Example: "The unemployment rate is often seen as a key barometer of the overall health of the economy."
Alternatives: "a crucial indicator" or "a significant measure".
Swap spreads have become a key barometer of financial health.
A key barometer of change will be whether the phone records collection program survives.
The September Yearling Sale at Keeneland has long been a key barometer for the global bloodstock market.
THE NEWS A key barometer of the industrial economy -- orders for durable goods other than transportation equipment -- fell 3.6 percent in January.
For now, though, insiders point to the 10% increase in deposits over the past year as a key barometer of progress.
Statewide, 61.5percentt of fourth graders, a grade educators consider a key barometer of literacy, met English-language standards, an increase of about 13 percentage points from four years ago.
Basildon has always been a key political barometer.
Somehow, the final 30 seconds of trading on Tuesday left a key market barometer, a widely traded futures contract linked to the Standard & Poor's 500 index, priced at exactly 911.00 -- the figure that remained on traders' computer screens around the world throughout yesterday's memorial service.
That is why Saadat Hasan Manto's provocative but thought-provoking short stories from the time of partition remain the key barometer of the hidden psyche of the early nation.
With the Dow approaching 9000, Hyman says the markets key barometer could meet some resistance amid profit taking next week.
The key barometer of small cap health, the Russell 2000 Index, was down 8.3% for the year at the close on Dec. 23, off by almost 36 points to 400.24.
