As for the tablet part itself, the rugged thin-and-light DT Research DT311H extends the company's focus well beyond its historic concentration on the point-of-sale market.

The tablet features a modern, businesslike design that's instantly at home in any enterprise. It is a competitor to thin-and-light tablet offerings from the likes of Getac, Xplore, GammaTech, and Panasonic, all created to be elegant, compact, lightweight tools for jobs on sales floors, warehouses, field offices, transportation, logistics, etc.

Measuring 12.3 x 8.2 x 0.86 inches and weighing a very manageable 3.6 pounds, the Intel "Broadwell"-based DT311H includes a full-slot Smart Card reader, has a hot-swappable 44.3 watt-hour battery, comes with speedy dual-band 802.11ac WiFi, and Bluetooth 4.0. Optionally available are a 4G LTE mobile broadband module, front and rear cameras, dedicated GPS, a 1D/2D barcode scanner, Class 1 (1,000 feet range) Bluetooth, and an NFC/RFID reader.

Before we get deeper into the tablet itself, the pictures below show how DT Research implemented the 2-in-1 concept, what it all looks like, and how it can be used.

The detachable metal keyboard has 81 keys with the general look and feel of the slender Apple keyboard that has pretty much replaced the giant, clunky keyboards of yesteryear. There's a 3-1/4 x 2 inch capacitive touchpad with multi-touch capability. The standard 12 function keys also provide dedicated Windows 10 functions such as Cortana, share, connect, and settings.

The keyboard hinge is heavy construction and very sturdy. Keyboard and tablet communicate via the standard dock connector, which means no Bluetooth link that may or may not work. The keyboard has a flip-out stand that keeps the assembly stable while using the combo as a notebook computer. The design of the stand, however, is such that the angle of the tablet is fixed.

Like some of the other major players in the rugged tablet market, DT Research has over two decades' worth of experience in industrial and commercial tablets. As such, the company has an excellent sense of what works in various vertical markets and what doesn't, and, if warranted, they have historically been quick in adopting new trends and technologies.

As a result, it doesn't surprise that the DT311H skillfully combines elements of a traditional rugged device with those of a state-of-the-art consumer media tablet. Below is a look at the DT311H tablet from the front and from all four sides. Note how for a rugged tablet it's a comparatively slender design, and how all I/O is placed behind protective covers. Unlike the smaller DT301S, the DT311H does have a fan (for now; starting March 2017, it's fanless), with air intake in the back and exhaust on top. The fan is virtually silent.

DT Research succeeded in creating a device that merges elegant, contemporary tablet looks with a brawny functional appearance. The protective bumpers are nicely integrated into the design and, unlike bumpers that are part of the housing, they are easy to replace. Physical controls are kept at a minimum. There are just four small buttons integrated into the design on the right lower part of the tablet. The power/sleep control is slightly recessed so that it isn't activated by mistake.

A trio of programmable buttoned labeled *, #, and + are, by default, used to toggle the onscreen keyboard, toggle the Windows menu, and execute the "Security" modern day equivalent of the old alt-ctl-del. A utility allows programming these buttons to whatever the job requires. Anything else is done onscreen.

The images below show the right and left sides of the DT311H tablet with the hinged protective covers open. The cover doors click into place. Care must be taken to make sure they are actually locked.

Rugged tablets usually don't have a lot of onboard connectors, and the DT311H is no exception. The tablet offers a 3.5mm audio jack, a power jack, and a single standard USB 3.0 port on its right side. There are tiny embossed symbol labels on the protective door. They are hard to see, but since the ports themselves are obvious, it's no big deal

The picture to the right shows the backside of the tablet, with its rubber hand strap removed.

Taking the DT311H apart is fairly simple. First you undo six small Philips screws to remove an access cover to an expansion slot compartment. It's not just a cover, though, as there's a small battery attached to it. Inside the compartment are the SIM card slot, and an expansion mini-PCIe slot as well as additional electronics.

The battery is custom-designed for the DT311H and is part of the tablet, i.e. there is no cover over it. The battery compartment itself isn't sealed, but the connector between the battery and the insides of the tablet is, and that's all that matters. The battery is securely held in place with a combination friction lever/lock.

As far as power goes, the DT311H battery uses Lithium-Ion technology and is rated 7.2Volts and 6,150mAH, which makes for 45 watt-hours. The advantage of this type of battery design is that it's easy to offer optional higher capacity batteries (that then may protrude a bit).

Next it's time to remove the plastic antenna covers, the protective I/O covers, and the corner rubber bumpers. That's not inherently difficult, but requires undoing a variety of different screws and bolts. Once that is done, the two halves of the DT311H come apart easily. Some caution is required though as there are three cables that must be disconnected before the two halves fully separate.

The overall construction of the DT311H now reveals itself. Except for the front bezel overlay and cladding, pretty much the entire tablet is magnesium. It's a very sturdy construction and neatly reinforced wherever needed, not the fragile featherweight kind often found in premium consumer tablets. Below you can see the two structural halves of the DT311H, top on the left and bottom on the right.

The important sealing between the two magnesium halves is via a fairly straightforward tongue-and-groove design that goes around the perimeter. In the groove sits a replaceable rubber seal.

All major components are mounted on backside of the tablet. The motherboard measures about 6.5 x 6 inches. It's clearly a custom design for this particular tablet, cut and contoured to fit precisely into its space inside the magnesium frame.

What's interesting is that although on the outside the 11.6-inch DT311H looks much like a larger version of the 10.1-inch DT301S that RuggedPCReview examined in detail a couple of months ago, inside the two tablets are very different in layout, design, and organization. That also extends to the cooling system which in the DT311H employs a standard fan instead of the passive cooling via heat sinks and heat spreaders in the smaller DT301S. Fans have their pros and cons. On the plus side, they are active cooling systems that can match cooling requirements to environmental conditions. Such designs minimize performance drop-offs at high operating temperatures.

But won't get water in through the fan's air exchanged slots? No, because the fan is mounted on the outside part of the magnesium frame. The fan itself is waterproof.

Of components and modules, we see an Intel Dual Band Wireless-AC 7265 2x2 WiFi and Bluetooth module. For WiFi, it's about three times faster than 802.11n, up to 867 Mbps with its two antennas both at the transmit and the receive end. No other components are in plain sight as many electronics are underneath very clean custom-made metal shielding. Whatever I/O there is — USB 3.0, an audio jack, and power — is edge-mounted on the motherboard.

There are a few visible wires, all leading to the various antennae that are located outside of the sealed metallic inner sanctum of the tablet. That's because antennae can't work inside a full metal enclosure.

That's mainly because a long time ago one of Intel's co-founders, Gordon Moore, stated that the number of transistors on a given surface area would double every 24 months. This became known as Moore's Law, and Intel built its processor development strategy around it. In what Intel calls their "Tick-Tock" cycle, the company has continuously been shrinking transistor size (so that more fit onto a chip) one year, and then redesigning and optimizing the circuitry the next to take advantage of the shrunken components. In this system, the 5th generation "Broadwell" chip in our review unit was a "tick" that shrank lithography, whereas the 6th generation Skylake (which is already in the DT301S and will become available in the DT311H in March 2017) is a "tock" processor optimization.

That rapid-fire succession of processor generations makes being "current" with Intel chips a fleeting proposition. Modern though the Intel 5th Generation Core processor circuitry inside the DT311H is, Intel has already released two newer generations, Skylake and then Kaby Lake. With Skylake Intel made their processors do more work in fewer cycles and handle more data per cycle. That was done via optimized parallel processing that keeps all available cores busy rather than having some just idle along.

But given that the DT311H is a fairly new design and DT Research always seems willing to provide its customers with the latest available technology, why did they not go all the way and skip to a 7th generation Kaby Lake chip for the March 2017 refresh? Probably because Kaby Lake does not officially support anything before Windows 10, and not everyone is ready to use Windows 10. As of this writing (February 2017), 47% of all desktop and laptop users still have Windows 7, and only 25% Windows 10 (see NetMarketShare). Which means that DT311H customers with their Skylake chip can still exercise their Windows 7 Professional "downgrade" option.

As is, we ran our production Intel Broadwell-equipped DT311H tablet through our standard PassMark benchmark suite to test its performance in various categories. To provide an idea of where the DT311H with its Broadwell Core-i7 chip fits in we're also listing the results of its 10-1-inch Intel Skylake-equipped DT301S sibling, Xplore's XSLATE R12 and B10 tablets, as well as Dell's Latitude 12 Rugged Tablet, GammaTech's 11.6-inch Durabook R11, and Getac's 11.6-inch F110 tablet in 2015 trim (it's been upgraded to Skylake since). Here are the results:

The tablets listed above are all premium high-performance industrial tablets that pack a considerable punch. There is remarkable performance parity in that class, and so bottomline benchmark numbers (PassMark numbers, anyway) usually come down to processor generation and how quick the storage subsystem is.

As is, in our testing the DT Research DT311H performed at a slightly higher level than all but one of the tablets equipped with 5th generation "Broadwell" chips, but wasn't quite as quick as the sole 7th generation product or the Skylake-powered DT301S. Impressively, the DT311H earned three bronze medals (PassMark CPU, 3D Graphics and Crystalmark overall) in our recent "Speed Demon" feature on the fastest rugged tablets ever benchmarked by RuggedPCReview.

When the DT311H becomes available with a Skylake Core i7 processor in March 2017, it should provide an additional boost in both performance and efficiency.

What impact does the DT311H's considerable performance and its bright, vibrant screen have on power consumption and battery life? As is our standard procedure, we used Passmark Software's BatteryMon power management benchmark utility to measure the DT Research tablet's power draw under various operating conditions.

First we set the Windows 10 power options to "Balanced" and display brightness to its lowest setting (0%). That way we saw an idle power draw of 6.5 watts. We then cranked the backlight up to 50%, and draw increased to 7.8 watts. Then we cranked brightness all the way up to 100% and saw 9.2 watts. That's with the tablet being awake, just idling along.

Next we set the Windows 10 power options to "Power Saver" and display brightness at its lowest setting (0%). That way we saw an idle power draw of 6.4 watts. We then cranked the backlight up to 50% and draw increased to 7.3 watts. Then we cranked brightness all the way up to 100% and saw 8.3 watts.

DT Research DT311H Power Draws (at idle)
Backlight level	Lowest (0%)	50%	Maximum (100%)
Power Saver	6.4 watts	7.3 watts	8.3 watts
Balanced	6.5 watts	7.8 watts	9.2 watts
Max Performance	7.0 watts	8.4 watts	9.8 watts

Finally, we set the tablet to "Max Performance." At the lowest brightness we saw an idle power draw of 7.0 watts. At 50% brightness draw increased to 8.4 watts. And at the maximum brightness setting, electric draw reached 9.8 watts.

What do those power draw figures mean in terms of projected battery life? The thin Li-Ion battery of the DT311H has a capacity of 44.3 watt-hours. Dividing that by the 6.5 watt minimum observed draw would indicate 6.8 hours of battery life with the system staying awake the whole time. In the maximum performance settings and with the backlight going at 100%, theoretical battery life would drop to 4.5 hours.

Bright, excellent 11.6-inch full HD display

The DT311H tablet's 11.6-inch display offers full 1920 x 1080 1080p pixel resolution, making for 16:9 aspect ratio and a sharp 190 pixels per inch. That's sharper than Dell's highly acclaimed 4k UltraSharp desktop monitors. The display surface is of the glossy variety seen today on virtually all tablets and smartphones. Indoors, the DT311H display is a very pleasant to use and work on.

But since many DT311H tablets will likely spend much time outdoors and on the job, how well does the display perform outdoors?

Not too terribly long ago, outdoor viewability was the weak point of most rugged mobile computing devices. Display technologies came and went, none yielding acceptable results. Eventually the industry decided that modifying conventional transmissive LCDs for daylight and sunlight use was the best available way to go.

That's done by reducing the display's internal reflection of ambient light so that, in conjunction with a reasonably strong backlight, there is enough contrast to make the screen viewable outdoors. This reduction of internal reflection is accomplished via a combination of polarizers, filters, coatings and elimination of air spaces between the various layers of the LCD.

Almost all mobile devices use this technology today but the exact implementation varies from manufacturer to manufacturer. As does the strength of the backlight (a stronger backlight means a larger battery or shorter battery life).

DT Research has plenty of experience in this and it shows. The DT311H display is not only excellent indoors, it also remains quite usable outdoors. The tablet's backlight is sufficiently strong to boost contrast and viewability in broad daylight, without being so strong as to quickly drain the battery in prolonged outdoor use.

Viewing angle is another display quality that we consider extremely relevant in tablets. It's important because tablets are held in various ways and looked at from various angles. What's on the screen must remain easily viewable regardless of the viewing angle, and there must not be any changes in color, contrast or brightness. That doesn't matter much when using notebooks or desktops because one generally looks at the display head-on, at a steady angle. With tablets it's different.

The DT311H display scores very high in that regard. It offers perfect horizontal and vertical viewing angles. Colors, brightness and contrast remain true and unchanged when viewed from above, below, left and right.

The picture above shows how good the perceived image on the DT311H display can be under ideal conditions, i.e. without background that can reflect on the display, and without direct sunlight. The picture below shows that outdoors lighting and external reflections affect even the best current displays. Both pictures were taken in broad daylight, midday, but without direct sun. Varying the viewing angle by a few degrees so that the sky reflects, and the image becomes less viewable and assumes a distinct magenta cast from the coatings.

Overall, the display of the DT311H is about as good as it gets with current display technology.

Digitizer: capacitive multi-touch and (optional) active pen

Like a growing number of productivity tablets, the DT311H has both 10-point capacitive multi-touch as well as an optional active pen. That's because while capacitive touch is optimal for the tapping, panning, pinching and zooming popularized by smartphones and media tablets, precision operations, artwork, and a lot of legacy Windows software greatly benefit from a pen. Here's a bit of history on that:

Using desktop operating systems on a tablet means somehow making things work without the keyboard and mouse they were designed for. That has always been a challenge. The earliest tablets in the beginning of the 1990s mostly had active digitizers with a special pen. Those pens were expensive and, lacking touch, the tablets were useless if the pen was misplaced or lost.

For those reasons, many tablets switched to resistive touch that worked with a cheap plastic stylus or even fingers. Resistive touch, however, lacked precision and was a poor match for use with Microsoft Windows. In the early 2000s, Microsoft improved active pen support in its Windows XP Tablet PC Edition initiative, but it wasn't enough to make tablets popular.

Widespread tablet adoption only came after first the iPhone and then the iPad popularized capacitive multi-touch with its effortless panning and pinching and zooming. Even capacitive touch, however, had a rough start on Windows because legacy Windows simply was designed for use with a mouse and not a pen. Microsoft tried to address that first with Windows 8 and then 8.1, but it wasn't until Windows 10 that capacitive touch became more feasible for Windows tablets.

With Windows 10, users can toggle between tablet mode and desktop mode (see screen shots below). The two modes have a similar look, but using them is quite different. Desktop Mode has the start menu, windows, and everything needed to use Windows legacy applications and tools. Tablet Mode (what Microsoft initially called "Metro" in Windows 8) means full-screen apps and almost everything is touch-optimized. It's still a work in progress, but definitely a step in the right direction.

Ever since the emergence of the Tablet PC over a decade ago, Windows has included handwriting recognition and a number of pen and touch utilities. Examples are the Math Input Panel, Snipping Tool, and Windows Journal. The latter is no longer in Windows 10 because of security concerns over Journal's JNT file format, but Journal can still be downloaded from Microsoft (here). Other pen utilities are still present, and they are now joined by Windows Ink.

To launch Windows Ink you tap the new pen icon next to the keyboard icon to access ink-enabled Sticky Notes, Sketchpad, and Ink Workspace. They are basic and works in progress, but they are additional evidence that Microsoft, slowly but surely, morphs Windows into a more touch and pen-friendly operating environment. I mention "pen" because Microsoft's initial Tablet PC initiative was very much pen-centric, whereas capacitive multi-touch remains very much finger touch-oriented.

DT Research addressed this issue in the DT311H by giving it both 10-point capacitive multi-touch and a high-precision active pen. They used the eGalaxPen that is pressure-sensitive (which means it's great for art and elegant writing) but, unlike the ubiquitous Wacom pen, does need a AAAA battery.

The screen shots below show some of the pen and ink tools. Clockwise starting from the upper left, the Windows Ink Workspace, the Sticky Notes, and two examples of how one can use the Windows 10 Sketchpad.

Most tablets currently available with active pens use either Wacom or Microsoft's nTrig, but there's much to like about the eGalaxPen. Ink goes on very smoothly and there is none of the annoying "rubber-banding" delay that mars the experience of using other pen technologies. Pressure-sensitivity works smoothly and elegantly in apps that support it, as does the erase function. The pen comes to life as soon as it's close to the tablet and that also automatically turns off finger touch. If not used, the pen turns itself off after a couple of minutes so as to conserve battery. The pen tip makes a clicking sound when pressure is applied during use, and we had to get used to that.

Unlike other active pens, the eGalax pen doesn't do "hovering" where the cursor follows the tip of the pen even if the pen does not touch the surface. Hovering lets the user know where, exactly, the computer senses the tip of the pen. Hovering, though, is also quite annoying since real pens don't have a little cursor following them. So the eGalaxPen actually feels much more like a real pen.

Docks, accessories, and peripherals

Since the DT311H1 doesn't have much onboard wired connectivity, DT Research offers a handy, compact optional desktop dock that adds dual DisplayPort outputs that support 4K UHD resolution, four USB ports, and RJ45 LAN.

Other accessories include a DisplayPort-to-HDMI adapter that also enables running dual external displays off the dock; a wall/vehicle cradle with LAN pass-through and two USB ports that accepts power through a cylindrical 19V plug or a 12V-24V pluggable Phoenix terminal block connector. We've covered the 2-in-1 keyboard earlier in this review, and DT Research also offers a separate keyboard tray with a USB keyboard for use with the wall/vehicle cradle.

Elegant tablet that can take a beating

Hundreds of millions are using tablets now, but most of those are too fragile for field or even enterprise use. That's why there are rugged tablets like the DT311H. Problem is that making a tablet rugged increases cost, size and weight. So designers and manufacturers of such heavy duty tablets must find just the right balance for their products: Tough enough for the job, attractive enough to appeal, but still affordable and handy enough for effortless use.

Thanks to its ABS+PC polycarbonate and magnesium-aluminum alloy construction, the DT311H is a lot sturdier and tougher than its light and elegant design suggests.

The specs state IP65 sealing, which means the device is fully protected against dust, and also protected against low pressure water jets from all directions, albeit with, according to the spec, "limited ingress permitted."

IP65 is pretty much the expected norm for tablets in this class. In essence, IP65 here means you can use it in the rain, it won't mind sitting in a puddle or being washed off, but dropping it into a stream isn't a good idea. And do make sure the protective doors are closed when using the tablet in wet conditions.

The standard operating temperature range is a very wide -4 to 140 degrees, making the system deployable almost anywhere, including in commercial freezers.

DT Research also claims MIL-STD-810G testing for drop, shock and vibration, as well as MIL-STD-461F certification for EMI and EMC tolerance. Here it would be good to see more detailed information in the spec sheet and promotional materials. Customers are interested in rugged tablets because they can handle more abuse, so specific information on just how much abuse should be included.

Subjectively, despite its elegant, contemporary design, the DT311H does look as tough and rugged as it actually is. As our internal inspection revealed, with its heavy-duty magnesium frame inside and the hefty rubber corner guards outside, the DT311H can handle a good deal of punishment. The tablet feels solid and trust-inspiring, too, without any flex or creaking. That said, it would be good to know what sort of strengthened glass DT Research used and also what sort of scratch resistance the metallic surfaces provide.

Summary: DT Research DT311H rugged 2-in-1 tablet computer

With the light and compact DT311H, DT Research offers a state-of-the-art, Intel Broadwell (and as of March 2017 Skylake) powered thin-and-light tablet that's tough enough to be deployed in a vast array of applications that require more durability and resistance to adverse environmental conditions than run-of-the-mill consumer tablets can provide.

As a tablet, the DT311H offers a bright, spacious, daylight-viewable 11.6-inch capacitive multi-touch display with full HD resolution, perfect viewing angles from all directions, and an optional active pen with a pencil-thin, pressure-sensitive tip.

Weighing a very manageable 3.6 pounds, the attractively designed tablet is functional, tough, and well protected.

Equipped with a full-size USB 3.0 port, 3.5mm audio jack, and a Smart Card/CAC reader, the DT311H can be custom configured with dual cameras, 1D/2D barcode scanning, NFC/RFID as well as discrete GNSS and mobile broadband.

The optional detachable keyboard converts the DT311H into a hybrid 2-in-1 device that can instantly provide full laptop functionality without the extra bulk and weight of a permanently attached keyboard. The addition of a 2-in-1 version of the DT311H is timely and certainly makes the platform that much more attractive.

An optional desktop dock provides dual DisplayPort outputs capable of 4K UHD resolution, four USB ports, and RJ45 LAN. A wall/vehicle cradle with USB keyboard tray is available as well.

All of this combines into a modern, state-of-the-art Windows 10 2-in-1 tablet hybrid solution with performance commensurate with that required for a broad range of even the most demanding field applications. -- Conrad H. Blickenstorfer, February 2017

DT Research DT311H Specs:

Status	Added 07/2016, full review 02/2017
Type	Rugged Mobile 2-in-1 Windows tablet
Processor	Intel 5th generation "Broadwell" Core i7-5500U (available March 2017: Intel 6th generation "Skylake" CPU and fanless design)
CPU Speed	2.4GHz (3.00GHz turbo)
Graphics	Intel HD Graphics 5500, 300/950MHz
CPU Thermal Design Power	15 watts
OS	Microsoft Windows 7 Professional or Windows 10 IoT Enterprise
Memory	8GB or 16GB DDR3L
Display	Outdoor-viewable TFT with LED backlight, anti-reflection coating (available March 2017: 800 nits display brightness)
Display Size/Resolution	11.6-inch/1920 x 1080 pixel FHD (190 ppi)
Digitizer	Capacitive multi-touch, optional active digitizer/pen
Keyboard	Optional detachable 81-key keyboard, 3 programmable buttons, RF button
Navigation	Stylus, touch
Storage	128GB to 512GB Flash
Expansion slots	1 x Smart Card reader, 1 x Nano-SIM card
Housing	ABS+PC bezel; magnesium structure/frame
Size	12.3 x 8.2 x 0.86 inches (312 x 208 x 22 mm)
Weight	3.6 lbs. (1.6kg)
Operating temperature	-4° to 140°F (-20° to 60°C)
Ingress protection	IP65
EMI/EMC	MIL-STD-461F
Altitude	unknown
Drop/shock	MIL-STD-810G (4-foot drop)
Humidity	0-90% non-condensing
Vibration	MIL-STD-810G
Regulatory	FCC Class B, CE, RoHS compliant
Power	Rechargeable, replaceable externally accessible 7.2V 6,150 mAH Li-Ion (44.3 watt-hours), hot-swappable
Cameras	Optional: front-facing 5mp camera, rear-facing 5mp back AF camera with LED flash (available March 2017: Secure Camera mechanical privacy shutter on the rear camera with software privacy control for both rear and front)
Sensors	Accelerometer
Security	(available March 2017: Encrypted SD Card Slot that uses software encryption from Windows 10 and TPM 2.0)
Interface	1 x USB 3.0, 1 x 3.5mm audio in/out, power
Wireless options	Intel Dual Band Wireless-AC 802.11ac WiFi, Bluetooth v4.0 LE (optional Class 1), optional: 4G LTE, HSPA+, GSM/GPRS/EDGE, EV-DO, Rev A and 1xRTT, optional: 1D/2D barcode scanner, NFC/RFID, u-blox M8 GNSS module
Price	Inquire
Product page	DT311H web page
Spec sheet	DT Research rugged tablet brochure (PDF)
Warranty	1, 2, or 3 year extended or no-fault options
Contact	DT Research 2000 Concourse Drive San Jose, CA 95131, USA Tel: (408) 934-6220 Fax: (408) 934-6222 Web: www.dtresearch.com

(copyright 2017 RuggedPCReview.com)