The BIPM standard for ambient dose equivalent in -radiation beams is identical to that used for air kerma measurements. The standard is located at the front of an ICRU spherical water-filled phantom to represent the human body. This BIPM facility is used to calibrate secondary standards for NMIs that do not hold a primary standard. No comparisons of ambient dose equivalent have yet been held.

Details of the BIPM standard are given in:

Perroche A.-M., Boutillon M., Measurement of ambient dose equivalent and directional dose equivalent in a ⁶⁰Co beam, Rad. Protect. Dosimetry, 1989, 27, 139-148;
Kessler C., Roger P., Re-establishment of the air kerma and ambient dose equivalent standards for the BIPM protection-level ⁶⁰Co beam, Rapport BIPM-2005/08, 7 pp;
Boutillon M., Allisy-Roberts P.J., Measurement of air kerma and ambient dose equivalent in a ¹³⁷Cs beam, Rapport BIPM-1996/07, 12 pp.