Procedure

PROCEDURE

Weighing procedure

  • Place the balance on flat surface. Rotate the knob upon which the analytical balance rests to manipulate the mercury movement. Ensure that the mercury drop is within the circle, which indicates that balance is placed at symmetry. View video
  • Take a clean dry petridish and find out its weight. Take about 5 to 10g of feed, place it in the petridish and cover the petridish. Find out the weight of Petridish with the feed. View Video
  • The temperature of hot air oven is to be kept at 105 ° C to 110 ° C. View Video
  • Place the petridish in the hot air oven partially opening the lid. View Video
  • The drying is continued for 8 to 10 hours.
  • After 8 to 10 hours close the petridish and transfer it to a desiccator for cooling. View Video
  • After cooling to the room temperature, find out the weight of petridish with dried feed. View Video
  • Again, place the petridish in hot air oven; continue the drying for another 30 minutes. 
  • Cool it in desiccator and find out the weight. If there is further reduction in weight, repeat the process of drying, cooling and weighing till you get a constant weight i.e., there is no more water to be driven off by heating. 
  • Due to loss of water, there will be a reduction in the weight of substance. This is taken as moisture content of the feed.

Calculation

  • Weight of Empty Petridish = X g
  • Weight of dish + Feed sample = Y g
  • Weight of dish + dried material = Z g

Moisture-Formula

  • Dry matter content of feed (%) = 100 - % of moisture

Alternative methods

  • There is a rapid method for determination of moisture. In this method the sample is dried at 130 ± 2 ° C for only 2 hours. After drying, the dried material is weighed and the moisture content is determined.
  • Use of Infrared moisture balance.
  • Toluene distillation method.

Methods to be adopted for different feed samples

S.No.

Type of feed

Method

Remarks

1.

Silage

Toluene distillation

Due to the presence of volatile compounds

 

  • Place the balance on flat surface. Rotate the knob upon which the analytical balance rests to manipulate the mercury movement. Ensure that the mercury drop is within the circle, which indicates that balance is placed at symmetry.  View video
Last modified: Wednesday, 28 March 2012, 5:42 AM