GENERATION, CONTROL, AND MEASUREMENT 



253 



Table 3-20. Spectral Absorbancy A and Transmittancy T of Standard 

 Solutions for the Calibration of Spectrophotometers" 



" Path length, 1 cm; temperature, 25°C. 



*" Potassium chromate (K2Cr04) 0.040 g 



Potassium hydroxide (85% KOH) 3.3 g 



Water to make 1000 ml 



■= Cobalt sulfate (CoS04-7H20) 10.3 g 



Sulfuric acid (specific gravity 1.835) 10.0 ml 



Water to make 1000 ml 



"^ Copper sulfate (CuSOrSHsO) 20.0 g 



Sulfuric acid (specific gravity 1.835) 10.0 ml 



Water to make 1000 ml 



