It's matrix scan driven,
There are eight that point to a, b, c, d, e, f, g fields and decimal points.
The other five are the common poles of each nixie.
Use the buzzer of the digital meter, or the diode file, the test is good, the pen is connected to the corresponding field will be lit, with the power supply, no digital meter with 3V power string a 220 ohm resistor is also OK.
There is no data of the digital tube, to master a method, not only know the function of the foot, but also the test is good or bad, I am measured.