CRT Computer Monitor Buyer's Guide

Know what to look for when buying a CRT monitor for your PC

The Cathode Ray Tube, or CRT, monitor is the oldest form of video display for PC systems. Many early computers had monitors that output to a standard composite video signal so the screen could display on a regular TV. As time progressed, so did the level of technology used. Here are the CRT monitor resolution specifications so you can evaluate these displays before purchasing one.

Monitor Size and Viewable Area

All CRT monitors are sold based on screen size. Screen size is based on the diagonal measurement from the lower corner to the opposite upper corner of the screen in inches. However, the monitor size doesn't translate into the actual display size. The monitor's tube is generally partially covered by the external casing of the screen.

Also, the tube generally cannot project an image to the edges of the full-size tube. So, when looking to buy a CRT, look at the viewable area measurement given by the manufacturer. This is typically approximately .9 to 1.2 inches smaller than the tube diagonal.

Older CRT monitors on a desk.
Emilija Manevska / Getty Images

Resolution

All CRT monitors are referred to as multisync monitors. These monitors can adjust the electron beam, so it's capable of displaying multiple resolutions at varying refresh rates. Here's a listing of some of the more commonly used resolutions along with their acronyms:

  • SVGA: 800x600
  • XGA: 1024x768
  • SXGA: 1280x1024
  • UXGA: 1600x1200

There are a variety of resolutions available that are between these standard ones that can also be used by CRT monitors. The average 17-inch CRT can easily do the SXGA resolution and may be able to reach the UXGA resolution. Any 21-inch or larger CRT can likely do UXGA and higher.

Refresh Rates

The refresh rate refers to the number of times the monitor passes the beam over the full area of the display. This rate can vary depending on the computer settings and graphics card.

All refresh ratings by manufacturers tend to list the maximum refresh rate at a given resolution. This number is listed in Hertz or cycles per second. For example, a monitor spec sheet may list something like 1280x1024@100Hz. This means the monitor scans the screen 100 times per second at the 1280-pixel-by-1024-pixel resolution.

So why does refresh rate matter? Viewing a CRT display over long periods can cause eye fatigue. Monitors running at low refresh rates cause this fatigue in a shorter amount of time. Typically, it's best to get a monitor that displays at 75 Hz or better at the desired resolution. 60 Hz is considered the minimum and is the typical default refresh rate for video drivers and monitors in Windows.

Dot Pitch

This refers to the size of a given pixel on the screen in millimeters. This was a problem in past years when screens that attempted to do high resolutions with large dot pitch ratings tended to have fuzzy images because of the color bleeding between pixels on the screen.

Many manufacturers and retailers don't list the dot-pitch ratings.

Lower dot-pitch ratings are preferred because these give the display greater image clarity. Most ratings for this are between .21 and .28 mm, with most screens having an average rating of about .25 mm.

Cabinet Size

One area that most consumers overlook when purchasing a CRT monitor is the size of the cabinet. CRT monitors can be bulky and heavy. If you have a limited amount of desk space, the size of the monitor you want to fit in the area is limited. This is particularly important for the monitor's depth.

Many computer workstations and desks tend to have shelves that fit around the monitor that also have a back panel. Large monitors in such an environment can be forced extremely close to the user or restrict keyboard usage.

Screen Contour

CRT displays have a variety of contours to the front of the screen or tube. Original tubes similar to TV sets had a rounded surface to make it easier for the scanning electron beam to provide a clear image. As technology progressed, flat screens arrived that had the contour on the left and right but a flat surface vertically.

Now, CRT monitors are available with perfectly flat screens for both horizontal and vertical surfaces. So, why does the contour matter? Rounded screen surfaces tend to reflect more light and cause a glare on the screen. Similar to low refresh rates, large amounts of glare on a computer screen increases the amount of eye fatigue.