Ambient Dose Equivalent, H*(d): The dose equivalent that would be produced by the corresponding aligned and expanded field in the ICRU sphere at a depth d on the radius opposing the direction of the aligned field. Parameter defined at a point in a radiation field. Used as a directly measurable proxy (i.e. substitute) for effective dose for use in monitoring of external exposure. The recommended value of d for strongly penetrating radiation is 10 mm. Directional Dose Equivalent, H'(d,Ω): The dose equivalent that would be produced by the corresponding expanded field in the ICRU sphere at a depth d on a radius in a specified direction Ω. Parameter defined at a point in a radiation field. Used as a directly measurable proxy (i.e. substitute) for equivalent dose in the skin for use in monitoring of external exposure. The recommended value of d for weakly penetrating radiation is 0.07 mm. Individual Dose Equivalent, Penetrating, Hp(d): See: dose equivalent quantities: personal dose equivalent. Individual Dose Equivalent, Superficial, Hs(d): See: dose equivalent quantities: personal dose equivalent. Personal Dose Equivalent, Hp(d): The dose equivalent in soft tissue below a specified point on the body at an appropriate depth d. Parameter used in the BSS as a directly measurable proxy (i.e. substitute) for equivalent dose in tissues or organs or (with d = 10 mm) for effective dose, in individual monitoring of external exposure. The recommended values of d are 10 mm for strongly penetrating radiation and 0.07 mm for weakly penetrating radiation.  Soft tissue  is commonly interpreted as the ICRU sphere. Recommended by ICRU [, 16] as a simplification of the two separate terms, individual dose equivalent, penetrating, Hp(d), and individual dose equivalent, superficial, Hs(d) defined in ICRU 39. Individual Dose Equivalent, Penetrating, Hp(d), and Individual Dose Equivalent, Superficial, Hs(d), defined in Ref