Testing the Used Fixer (by HCM)

These photos show students testing the fixer that has been saved after previous use.

 A small amount of fixer was poured into the bottle cap, and the clipped piece of the film (the leader) was placed into the used diluted fixer.

  Test how long it takes for the film to clear. If the clearing time for the used fixer reaches twice the clearing time for new fixer, the used fixer could be regarded as exhausted. 

~HCM~

Week 4