PH indicator range: 

1.2 (orange) -3.0(yellow)

6.5£¨yellow-brown£©- 8.0£¨purple£©

Maximum absorption wave-length£¨nm£©:

¦Ë₁£¨PH1.2£©  503---506

¦Ë₂£¨PH 3.0£©  430---435

¦Ë₃£¨PH 6.5£©  430---435

¦Ë₄£¨PH 8.0£©  557---560

Mass absorption coefficient£¨L/cm¡¤g£©

¦Á₁ £¨¦Ë₁£¬PH 1.2£¬dry sample£©110---123

¦Á₂ £¨¦Ë₂£¬PH 3.0£¬dry sample£©60---68

¦Á₃ £¨¦Ë₃£¬PH 6.5£¬dry sample£©62---72

¦Á₄ £¨¦Ë₄£¬PH 8.0£¬dry sample£©115-130

Solution test in alkali: qualified

Loss on drying: 1.0%max

Residue on ignition (as sulfate): 0.2%max