Thanks. My order arrived.
There seems to be a lot of confusion about with regard to the pinout... For the 2DW233, I'm finding that the common cathode is the pin connected to the case, and the others are the two anodes. Vz of each of the individual diodes is around 5.36V and the pair in series (i.e. between the two non-case pins) is about 6.17V.
But is each of the diodes exposed to the outside a TC zener reference, or is the pair used in series the TC reference?