Neon & Cold Cathode frequently asked questions list.

What is the difference between neon and cold cathode?

Cold cathode and neon is essentially the same. Both can be bent and shaped to conform to almost any configuration; and with minimal space between lamps, shadow less cove or indirect (shadow effect) lighting can be achieved. Differences are cold cathode lamps tend to be larger in diameter and require a higher amount of milliamps than neon tubes and they contain not only a small amount of mercury but the inert gas Argon instead of Neon.

How is the glass tubing shaped to my requirements?

The shaping of glass is carried out by hand from a working drawing. The correct colour and diameter glass for the specification is heated by rotating and rocking it over a flame. Once the glass has started to bow under its own weight it is then shaped to the drawing.

How do neon and cold cathode tubes work.

Both works in a similar way, gas is pumped into the tube under low pressure, cold cathode tubes have a small amount of mercury added. Each end of the tube has a metal electrode. When a voltage is applied the neon gas ionizes, causing electrons to flow through the gas, these excite the neon atoms making them vibrate and emit light energy. With the cold cathode tube, mercury vaporises, allowing the tube to burn brighter than if only argon was used.

How is the gas put in the tubes?

After the glass has been shaped it has electrodes attached to each end. One of the electrodes is a tubulated electrode which has a small stem canal that runs into the top of the electrode. The stem/tubulation is then attached to the manifold of the bombarder by fuseing the stem of the manifold and the stem of the tube.

A vacuum pump then removes the air from the tube, a high voltage is then applied to the tube, and this heats the tube up to over 250 degrees centigrade, burning off any impurities in the glass tube.

The tube is then allowed to cool; a small amount of inert gas is put into the tube via a value with a flask attached to it. The tube is then removed from the manifold by heating up the stem, creating the seal.

Is neon or cold cathode dangerous?

Neon and Argon gases are inert gases and therefore not dangerous. As with normal everyday fluorescent lamps found in kitchens, schools and many commercial premises there are small droplets of mercury contained within the tube. The small droplets are only contained within tubes that have argon and are safe as long as the tube remain intact. Improper handling can be a threat to both the environment and health.

Neon and cold cathode tubes are powered by both high and low voltage transformers, and should always be installed by fully trained and skilled engineers.

What is the life expectancy of my neon/cold cathode?

The Life expectancy of a tube has a few determining factors, the first of which is the quality of the bombarder, older glass system bombarders will do the same job as newer systems, but the longevity and final quality of a section is greatly decreased due to the ineffectiveness of the vacuum.

The next determining factor for the life expectancy of a tube is the amount of power being passed through it. If the voltage is calibrated wrongly the life of a section can be as low as a few months.

When correctly bombarded and calibrated a neon sign can last up to 15 years or as much as 100,000hrs. A cold cathode sign can last up to 48,000hrs and sometimes can reach as much as 60,000hrs. After 5 years cold cathode may experience a small drop in lumen output, neon will never experience a lumen drop.

Can neon and cold cathode be animated so as to move?

Neon and cold cathode can be animated in a variety of ways using faders, chasers, dimmers and sequencers. This however can take is not a simple process and take time in designing and implementing, but the effects can be astounding.