KEY TERMINOLOGIES ASSOCIATED WITH GAMMA IRRADIATION
- Absorbed dose:
Refers to the amount of energy transferred to the product by radiation. Measured in Gray. 1 gray is equal to 1J/kg .
- Source strength:
Refers to the strength/ power of the radiation source used for processing of the products. Common units of measurement are Curie (Ci), Becquerel (Bq).
1 Ci = 3.7 X 1010 Becquerel
1 Becquerel = 1 Disintegration/ second
- Plant throughput:
Refers to the amount of product (in Kg’s) that can be processed by an irradiation plant on a hourly, daily or monthly basis.
Unit: Kg/ hr., Kg/ day etc.
- Radiation absorption efficiency ( ):
The fraction of radiation energy emitted by the radiation source that is absorbed by the total product during the irradiation cycle.
It is calculated by the formula
- Dose uniformity ratio (DUR):
When a product is exposed to Gamma rays, different locations in the product package get different doses. The ratio between the maximum dose to the minimum dose absorbed by the product in a given package is known as DUR. It is calculated by the formula = Maximum dose / Minimum dose
- Product Changeover Time:
The total time taken to replace one product by another (of varying density), for irradiation is known as changeover time.