The SI-39G Geiger tube is a very good all-purpose tube made to detect both Beta and Gamma radiation. Similar in construction to the SI-10BG, SI-11BG, SI-BG, and SI-22BG, the SI-39G has a slightly longer internal cathode sleeve to enhance its sensitivity. It was designed to snap into ¼” fuse holder-type clips in one of the many specialized military Geiger counters used during the Cold War period. https://www.youtube.com/watch?v=82g8bY2YEFw
SI-39BG
$37.95Price
1. Cathode Material: 446 Stainless Steel
2. Anode Material: Tungsten
3. Construction: Glass Envelope
4. Length: 93.5mm (3.7”)
5. Approx. Diameter: 7.5mm (0.295”)
6. Recommended Anode Resistor: 5.1M
7. Starting Voltage: 360-440v
8. Recommended Operating Voltage: 400v
9. Operating Voltage Range: 360v-440v
10. Sensitivity: Gamma and Beta
11. Lifetime Pulses (est.): 1 x 10(10) (10 billion pulses or 1900 years at normal background CPM)
12. Background CPM: 10 (in Southern California area)