SAN FRANCISCO — With the tap of a finger, Christian Gastón Palmaz can use his iPad to remotely control one of the most sophisticated winemaking operations in Napa Valley.

The apps Palmaz and his information technology staff created for the iPad tablet enable them to monitor and adjust the temperature in large tanks lined with sensors to more precisely control fermentation. With the iPad at its heart, the system has replaced a labor-intensive process that required a winemaker to constantly draw and test samples and then manually adjust the temperature.

"All the time she's doing that, she's not tasting wine," Palmaz said. "This gives the winemaker back 50% of her time."

Although Palmaz Vineyards is a relatively small business, its enthusiastic embrace of iPads represents something much bigger taking place at Apple Inc.

The company long known for its focus on consumers and education is now using the iPad to sneak into the lucrative business market. Although overall use of tablets by businesses is small, the iPad has helped Apple stake out a commanding lead for mobile devices in business markets long dominated by PCs and laptops running Microsoft's Windows.

"Apple has become the de-facto standard in a lot of commercial enterprises in terms of tablets," said Tom Mainelli, an IDC research analyst. "It's an interesting turn of events."

On Tuesday, Apple is expected to unveil new versions of its iPad and iPad Mini at a media event in San Francisco. Such events tend to highlight how the devices are used by regular folks or students to read, watch videos or play games.

But there are signs that among consumers, there's a bit of tablet fatigue. During the last quarter, sales of iPads declined to 14.6 million units from 19.4 million units the previous quarter and 17 million for the same quarter last year.

In part, the drop was because Apple has taken longer than usual to introduce new tablets. And sales of tablets overall showed declines last quarter.

Still, the iPad's drop, coming after three years of astounding growth that upended the PC and laptop markets, was surprising enough for Barclays Capital analyst Ben Reitzes to declare in a note to clients, "IPad clearly has the flu."

Many analysts are now projecting that the growth rate of iPads will slow and possibly plateau in the next few years.

How to kick-start that growth? For some analysts, the answer is to get more iPads into businesses.

"While Apple's roots are in consumer and creative segments, we believe that the company may be well served by a greater focus on the corporate market in the future," Reitzes recently wrote in a note to clients.

So far, the signs for Apple are promising.

Good Technology, which makes mobile security applications and tracks mobile device use by businesses, found that 72% of mobile devices activated by businesses ran on Apple's iOS. Looking at just tablets, 90% were iPads, according to its study.

It's an impressive lead for a company that just a few years ago barely had a pulse in the business world.

"We think we're just at the beginning of this market," said Lynn Lucas, Good Technology's chief marketing officer. "The use of mobile in the enterprise is still very low."

The iPhone got Apple's foot in the door at many businesses that had been traditionally closed to them. Executives and average employees brought the iPhone for personal use but then insisted on using it at work, pressuring IT managers who were more comfortable with Windows to relent and make changes to support them.

That laid the groundwork for the iPad, which shares the same iOS mobile operating system. But the iPad's larger display and touch interface has enabled it to perform a wider range of tasks in the workplace.

Curtis Kasefang, a senior consultant for Theatre Consultants Collaborative, which designs stages, said the iPad quickly became indispensable to the company, which operates virtually with no central office.