Specifications include, but are not limited to: The services of a company to perform calibration to meters used for air quality testing from a contract between the successful bidder(s) and the MDE. A. Use a radioactive sealed source(s) that: 1 Approximates a point source; 2 Is a certified, NIST-traceable, standard source that has an activity or exposure rate accurate to within 5%; if the activity or exposure rate is determined by measurement, document the method used to make the determination and traceability to NIST; 3 Emits the type of radiation measured; 4 Approximates the same energy (e.g., Cs-137, Co-60) as the environment in which the calibrated device will be employed; and 5 Provides a radiation dose rate sufficient to reach the full scale (<1000 mR/hr) of the instrument calibrated. Use the inverse square and radioactive decay laws, as appropriate, to correct for changes in exposure rate due to changes in distance or source decay. B. A record must be made of each survey meter calibration and retained for 3 years after each record is made (10 CFR 20.2103(a) and 10 CFR 35.2061). C. Before use, perform a daily check (with a dedicated check source) and battery checks.