MRC:
A recording of the physical,functional,and performance characteristics for an item of supply.TEXT
General Description:
Plastic w/square base; base scale graduated in logarithms to base 10 of numbers 0.5 to 1000; elevation scale difference on the disc shall be graduated in logarithms to base 10, of one half the sine of twice the angles from 3 minutes to 45 degrees; horizontal distance scale on the disc shall be graduated to the logarithms base 10, of the cosine squared of the angles from 0 to 45 degrees