If you don't have a CRT tester, you can still use an ohmmeter to check for continuity between the filament pins. Infinite resistance means the filament is burned out and the tube's a dud. Resistance of a few ohms means the filament is intact (and most likely, the tube holds vacuum, since the filament would quickly burn out if powered up when vacuum was lost).
My T-100 uses a 10BP4. For that tube, or a 12LP4 for that matter, the filament pins are 1 and 12.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html