Functions and requirements of getters

The role of getters in electric light sources is:

1. Reduce all residual gases in vacuum lamps to a minimum, and absorb the gases released by the parts and glass shells in the lamps, so that the vacuum degree in the lamps can be improved and maintained.

2. In gas-filled lamps, getters selectively remove useless impurity gases in the filled gas and gases released by the parts and glass shells in the lamps, thereby maintaining the purity and composition of the required gases.

3. With the help of getters during exhaust, the vacuum degree in the lamps can be quickly reached and maintained to improve production efficiency.

Due to the above-mentioned role of getters, the getters of electric light sources must meet the following requirements:

1. In a fairly wide temperature range, getters have greater chemical activity against a variety of useless impurity gases in the lamps, not only have high gas absorption capacity (large gas absorption volume and high gas absorption rate), but also can firmly hold the absorbed gas.

2. At the working temperature of the lamp, the getter itself must have a sufficiently low saturated vapor pressure, otherwise the vapor of the getter itself will destroy the vacuum of the vacuum lamp or contaminate the gas in the gas-filled lamp.

3. For the internal parts of the electric light source, the required filling gas, the luminous material, etc., the getter must have high chemical stability and cannot react chemically even at the working temperature of the lamp.

4. The presence of the getter should not affect any characteristic parameters of the electric light source.

5. The getter is easy to store during the production cycle, the manufacturing process is simple, and the price is low.

In the electric light source industry, the getters used are usually divided into two categories: evaporable getters and non-evaporable getters.