explain the purpose and importance of checking the following during local exhaust ventilation thorough examination and testing stage a.check and verify the access doors and hatches

b. check and look for any sign of moisture or water damage

c. check the differential pressure across the filters

d. check for any signs of by pass around the filters

e. verify the fan operation and alignment

f. check and verify the belt tension and alignment

g. verify the fan size is correct for the system

h. verify the condition of the fan blade and motor

I. verify if the filter media is correct type and rating

j. inspect the system for any visible corrosive