Scintillation Counter Balance Point

Identify all the controls on a liquid scintillation counter using the instrument manual as a guide. 

Place 15 ml standard scintillation fluid into a scintillation vial. 3-5. Add 0.50 ml radioactive ( C) toluene (containing approximately 1-2 X 10 dpm/ml) to the vial. The amount of radioactivity per unit volume should be accurately known. Precisely standardized toluene solutions may be obtained commercially and may be used in place of those described here. 

Repeat step 3-8 using the data obtained in step 3-9. 

The values yielding maximum counting rates in these figures are the coarse and fine gain settings of the balance point. 

Set the gain control to the balance point for the isotope being used, H in this case (step 3-12). 

---