Each half-value layer (HVL) halves the rate; each tenth-value layer (TVL) reduces it to one tenth. Enter a shield thickness and layer value to find the transmitted rate, or solve for the thickness needed to meet a target rate. Layer count is the thickness divided by the layer value.
If the starting rate already meets your target, no additional shielding thickness is needed. Fractional layers are allowed. If you specify a slab increment, the calculator rounds thickness up and checks the resulting rate against the target.
Use a layer value appropriate to the material, density and photon energy in your problem. This model does not include a buildup correction.
Results, input checks, source references and accuracy notes are free. Paid membership adds the step-by-step solution and calculator keystrokesKey sequences for 14 calculator optionsScientific — commonly exam-legalTI-30XaTI-30X IIS / IIBTI-30XS MultiViewTI-34 MultiViewTI-36X ProCasio fx-991EX ClassWizCasio fx-115ES PlusCasio fx-300ES PlusSharp EL-W516TOn screen, no handheld neededRadCon calculator (on screen)Graphing / programmable — practice at homeTI-84 Plus CE (and TI-83/84 family)Casio fx-9750GIII / fx-9860GIIIHP 35sNot sure which you haveGeneric scientificChoose the calculator you use to practice. Check with your testing site which models are allowed in the exam..
Already a member? Open the full calculator.
Use this calculator for study and reference. For operational radiological work, follow your site’s controlled procedures and approved references.
Read the handbook for free, then use study sessions and practice tests to check what you’ve learned. Membership includes worked solutions and progress tracking. Access is currently by invitation; sign up to hear when it opens.