What is Hysteresis material constant "ηB"

I had downloaded the datasheet from EPCOS http://www.epcos.com/blob/528850/download/3/pdf-n27.pdf,
I want to know the remanence Br of the ferrite, there is parameter name Hysteresis material constant "ηB" on table of Page2, could someone tell me what it is ? How can I calculate the Br from the parameter ?

Regards,
rocky

I had donwload the ferrite core datasheet from EPCOS, there is a parameter call Hystersis Materials constant "nB". What it is ? How can I get the remananece Br ?
Regards,
rocky

As explained in the general ferrite informations, ηB describes hysteresis losses, in so far it's not directly related to Br. Br depends on test conditions and can be read from magnetization curves.

I checked the epcos ferrite book on my shelf:

So it"s useful for estimating core losses, but not Br (though the two are certainly correlated to some extent).

In general you can't predict Br exactly, it depends on the overall H stimulus you give the core (and air gap of course). The magnetization curves can, at the very least, give the worst case Br with no gap and a large magnetization.

It still not easy understand. Could you give me an example how to estimate the core loss base on the "nB" on datasheet on http://www.epcos.com/blob/528850/download/3/pdf-n27.pdf ?

switching frequency 50KHZ, dB=150mT , what is the core loss ?