CRTs can still be found in art museums, however, where they are used to display video artwork. Since their introduction to the consumer market, artists working with video have embraced CRT monitors not only as display devices, but also as sculptural elements. A notable example of a CRT artwork is Diana Thater’s The best animals are the flat animals (stacked monitor edition).
For this piece, Thater filmed zebras at an exotic animal farm and presented the footage on five CRT monitors stacked directly on the gallery floor. Here, the CRTs are more than just video displays—they are integral to the artwork’s sculptural presence.
One of the five CRTs for The best animals are the flat animals displaying one of the five videos.
Conserving an artwork that uses CRTs poses a serious challenge; CRTs haven’t been manufactured in almost 20 years, resulting in a limited and continuously decreasing supply. Also, CRT artworks like The best animals are the flat animals cannot be migrated to flatscreen monitors without undermining the artist’s intent. Therefore, the conservation of these artworks relies on maintaining the function of the CRT.
But first, what are CRTs?
CRTs are complex technological objects; beneath the plastic housing, the television utilizes multiple electrical systems to create a moving image. A glass vacuum tube serves as the vessel for an electron gun that directs beams of electrons across the screen to create moving images. This process relies on high voltage and complex circuitry, which can degrade or fail over time.
Diagram of a CRT with the internal components revealed
Illustration by Taylor Healy
As CRT technology and repair skills fade into obsolescence, conservators are stepping in to maintain and repair these televisions, ensuring the knowledge needed to keep them running is not lost. While the five TVs for The best animals are the flat animals are in good working condition, the media conservation lab is establishing a set of tools and procedures for CRT repair before issues occur. A time-based media conservator’s toolkit now must resemble that of an old TV repair person rather than a traditional conservator’s toolkit filled with cotton swabs, brushes, and scalpels.
Here are five of the most useful tools for keeping CRTs exhibition ready:
#1 Signal Generator
Calibration is an essential part of ensuring that the TV displays the artwork correctly. Over time, the way that the CRT represents the image might become distorted. Signal generators were used extensively by the TV broadcasting industry to ensure that the colors of each program were accurate before sending them out to the masses.
Signal generators create standardized video test patterns that can be used as a reference for calibrating a CRT’s color and geometry.
Testing the color and geometry of a crt
In both photos, the signal generator (far left) sends a signal to a small test CRT (middle) and then to the malfunctioning CRT (right). The small test CRT displays the color bars and crosshatch pattern correctly, serving as a reference for the distorted image on the large CRT.
From left to right: signal generator, test CRT, and malfunctioning CRT
Both CRTs are displaying a color bar test pattern from the signal generator.
From left to right: signal generator, test CRT, and malfunctioning CRT
A geometry test signal is being displayed on both CRTs.
#2 DEGAUSSING COIL
Over time, the way that a CRT displays color may become distorted due to stray magnetic fields. A degaussing coil can be used to treat color distortion by correcting where the flow of electrons from the electron gun lands on the screen. (See illustration above.)
The degaussing coil is an electromagnet that is rotated manually around the face of a CRT with color distortion.
Gif of a CRT being degaussed with a degaussing coil
While degaussing a CRT, a solid color from a signal generator should be displayed. The degaussing coil will temporarily create colorful rings as the TV becomes de-magnetized and the trajectory of the electron beams are corrected.
If degaussing does not correct color distortion, the technique serves as a diagnostic tool indicating that the distortion is due to an internal component issue.
Before and after
Before degaussing (left) and after (right)
#3 CRT Color Analyzer
For artworks that require more than one CRT for display, such as Thater’s The best animals are the flat animals, it is important that the colors rendered on the monitors are uniform.
A CRT color analyzer precisely measures the hue and brightness of the CRT screen through a probe, similar to the process of color matching a paint chip at the hardware store.
Measuring the white test pattern of the small monitor with the color analyzer
The numbers are compared against established standards for white.
The analyzer probe is suctioned to a CRT monitor that is connected to a signal generator. The color analyzer displays numerical color information that can be compared against established illuminated color standards.
#4 High Voltage Gloves
Many of the components inside of a CRT operate with dangerous high-voltage electrical current, posing a risk for electrocution for anyone who performs internal maintenance. Voltage insulating gloves protect you from electrocution when working on the internal components of a CRT.
The author wearing high voltage gloves to remove CRT circuit boards
High voltage gloves are an essential personal protective equipment (PPE) used when treating the internal components of CRTs.
#5 Thermal Imaging Camera
A thermal imaging camera is a type of infrared (IR) camera that can be used to highlight heat generated in CRT circuit boards that is not visible to the human eye. Excessive heat or no heat at all can indicate broken circuits or short circuits. Once these faulty components are identified, they can be replaced.
Visible light image inside of the CRT
IR image of the the CRT off
IR image of the the CRT right after being powered on
IR image of the the CRT that has been on for 30 minutes
Final Thoughts
Maintaining CRT-dependent artworks is complex and, unsurprisingly, there are many more tools than the five outlined above. Time-based media conservators are always searching for new tools and resources. Documenting and sharing the tools and methods for the maintenance of CRT-dependent artworks is a vital part of keeping pieces like The best animals are the flat animals functional and exhibitable for years to come.
—Bird Nord, McMullan Arts Leadership Intern, Conservation and Science, Time-Based Media
