Monitor Arms

Check the display’s weight without its original stand, the mounting-hole pattern, and any recess or obstruction around those holes. Treat the advertised screen diagonal as secondary: Ergotron states that its LX can exceed the listed 34-inch approximation if the display remains within the mount’s weight limit, and it specifies 75 x 75 mm and 100 x 100 mm VESA patterns. Confirm every limit for the exact arm and configuration.

A clamp attaches at an accessible desk edge and usually avoids drilling; a grommet mount passes through a suitable hole and may work where edge access is poor. Measure the desktop and hole before buying because ranges differ by model. For example, StarTech lists a 20–100 mm desktop range for this arm’s desk clamp, a 20–50 mm range for its grommet clamp, and a 10–60 mm grommet-hole range. Also confirm that the desk structure can carry the arm and display load.

Choose enough lift, reach, and tilt to place the screen directly in front of the user without leaning or turning. OSHA’s workstation guidance recommends at least 20 inches of viewing distance, generally 20–40 inches, with the top of the monitor at or slightly below eye level. It also advises positioning the screen perpendicular to a window and adjusting tilt to limit glare. Required range can change with user height, bifocals, desk depth, and sitting or standing posture.

Neither layout is universally preferable. A dual system can reduce the number of desk mounts and coordinate two displays, but its per-screen limits and geometry may be more restrictive. StarTech’s cited dual arm supports 9 kg per display, while Humanscale describes different limits for a single monitor and an optional dual-monitor crossbar. Compare each screen’s weight, desired side-by-side or stacked position, independent movement, and the total load applied at the desk mount.

Sagging or drift can result when the display falls outside the supported load range, the spring or counterbalance is not adjusted for the installed weight, or a joint or desk attachment is loose. StarTech describes spring-assisted height adjustment with user-adjustable tension, while Humanscale identifies a weight-compensating spring and counterbalance indicator on its M8 line. Install the display first, follow the exact manual’s adjustment sequence, and retest after changing the monitor or accessories.

Look for a stated motion-cycle test, a written warranty, accessible installation documents, and hardware that can be reconfigured without replacing the whole assembly. Ergotron says the cited LX passes a 10,000-cycle motion test and carries a 10-year warranty. StarTech also states a 10,000-cycle test and 10-year warranty for the cited dual arm. These claims do not guarantee service life, but they are more useful than an unsupported durability label and should be checked for the exact model and region.

Route power and signal cables through the arm’s intended guides while leaving enough slack at every moving joint and at the display connector. Move the arm through its full range before regular use to check for pulling, pinching, or sharp bends. Humanscale describes top-to-bottom cable management on the M8 line, and StarTech lists adjustable cable management on its dual arm; the precise path and retention method still depend on the model’s manual.