This is the biggest geiger tube I have seen! I’ve bought one for 25€ at eBay.
Glass tube, thermostable. Cathode: tungsten powder.
- Length of the plateau: not less than 200V
- Slope of the plateau: 0,07%/V
- Recommended working voltage: 900V
- Dosimetric characteristics N = 0.1 imp / min · cm2 at 1 microR / s Nmax = 2 · 104 Nf = 31
- Service life: impulses 5·107
- Range of working temperature: +10 / +250 °C
- Dimensions: ∅27 x 400mm 92g