Answer / me_prashant

Untapped Density = bulk density
Bulk density is the simply fill capacity of any vessels.

we take a 100ml cylinder and fill it with any
substance(Approx-x gram) and read the volume of cylinder.
then the bulk density= weight of substance/ml of cylinder.
unit = gm/ml or gm/cc
but the tapped density is that density which measure after
tapping according to monograph (USP-1, USP-2)we use it when
ever the volume of substance not to be constant.

(for USP- 1 it should be 350 stocks. and for USP -2 it
should be 250 stocks.which we use in calibration of Tap
density tester.)

Answer / spln

Bulk Density (0 taps or Untapped): As is volume in
g/ml.This is called as apparent volume.

Tapped Density: after tapping only we can measure the qty
as g/ml. As per USP two types of methods is there, Method-
I&II.
Based on the powder nature tapping are fixed.500 taps, 750
taps & 1250 taps.(Varience% is NMT 2%)
Naturally all powder grades are fixed in 1250 taps.

After 1250taps also varience is more, then go to USP-II
method or any customer requirement is there then we can use
Method-II.

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