Lead Equivalence of various materials

This section presents of useful table of lead equivalence for a number of typical building materials. Use caution when using this data as its from pulsating potential x-ray generators with narrow beams. However, from an educational perspective its quite useful when thinking about the design of hospital diagnostic treatment rooms, by looking at where shielding credit could be claimed from the constructional materials used.

  • Lead Equivalence of Various Materials for Narrow X-ray Beams Table 4.7 (1)

Lead Equivalence of Various Materials for Narrow X-ray Beams Table 4.7 (1)

Lead Equivalence of Various Materials for Narrow X-ray Beams Table 4.7 (1)
Lead Equivalence of Various Materials for Narrow X-ray Beams Table 4.7 (1)

Example of using the table

In the example which follows we have converted all imperial units to SI units.

Assume you have a 150 kV x-ray source.

Assume you have a 23 cm (9 inch) thick standard brick of 1.6 density (i.e. 1.6 kg/m3 or 100 lb/ft3)

The table shows that the lead equivalence under these conditions is 2 mm lead.

It can be shown that 2 mm of lead (at 150 kV) will provide two TVL (10th value layers) which is 10-2 transmission. (See section 4.8 of course resource in order to obtain this conversion).

So the 23 cm standard brick (1.6 density) will provide the same shielding as using 2 mm of lead, which will provide a 10-2 reduction of x-ray dose rate on the safe side of the shield for a 150 kV tube.

Note that the above deviation is for educational purposes only. That said, modern literature indicates that the TVL for 150 KV x-rays is 0.95 mm which is practically 1 mm. Therefore the above analysis would work in a real world situation.