Item Name

Added Impurity (%)

Other Impurities (%)

Electric discharged power (eV)

Color code

Pure Tungsten electrode

---

< 0.2%

4.5eV

Green

Thoriated Tungsten electrode

ThO₂ (0.90% ~ 1.20%)

< 0.2%

2.0eV ~ 3.0eV

Yellow

ThO₂ (1.80% ~ 2.20%)

< 0.2%

2.0eV ~ 3.0eV

Red

ThO₂ (2.80% ~ 3.20%)

< 0.2%

2.0eV ~ 3.0eV

Violet

ThO₂ (3.80% ~ 4.20%)

< 0.2%

2.0eV ~ 3.0eV

Orange

Ceriated Tungsten electrode

CeO₂ (1.80% ~ 2.20%)

< 0.2%

2.7eV ~ 2.8eV

Grey

Lanthanated tungsten electrode

La₂O₃ (0.80% ~ 1.20%)

< 0.2%

2.8eV ~ 3.2eV

Black

La₂O₃ (1.30% ~ 1.70%)

< 0.2%

2.8eV ~ 3.0eV

Golden

La₂O₃ (1.80% ~ 2.20%)

< 0.2%

2.6eV ~ 2.7eV

Azure

Yttriated Tungsten electrode

Y₂O₃ (1.80% ~ 2.20%)

< 0.2%

2.0eV ~ 3.9eV

Blue

Zirconiated Tungsten electrode

ZrO₂ (0.20 ~ 0.40%)

< 0.2%

2.6eV ~ 2.7eV

Brown

ZrO₂ (0.70% ~ 0.90%)

< 0.2%

2.6eV ~ 2.7eV

White

composite electrode

CeO₂, ThO₂, La₂O₃, ZrO₂, Y₂O₃ (1.50% ~ 3.00%)

< 0.2%

Grass green