Blinky's Lab Geiger Muller Tube Conversion Factors.
This is a list of known or calculated conversion factors that I have gathered over the years.

RH = values from RH Geiger

		Tube				uSv/h/CPM	  CPM/uSv/h
		SBM20 				0.006315	= 158.35
		SBM20 				0.0057 - RH	= 175.44
		SI29BG 				0.010000	= 100
		SI29BG 				0.0082 - RH	= 121.95
		SBM19 				0.001500	= 666.67
		SBM19 				0.0021 - RH	= 476.19
		STS5 				0.006666	= 150.02
		STS5 				0.0057 - RH	= 175.44
		SI22G 				0.001714 	= 583.43
		SI3BG 				0.631578	= 1.58
		SBM21 				0.048000	= 20.83
		LND712 				0.005940	= 168.35
		LND712				0.00812	- M	= 123.15
		SBT9 				0.010900	= 91.74
		SBT9 				0.0117 - RH	= 85.47
		SI1G 				0.006000	= 166.67
		Robotron 70 013		0.001667	= 600
		HH614				0.01462	- M	= 68.4
		SBT-11A				0.0031 - RH = 
		LND-7312			0.0030 - RH = 
		
		
		
		
SBM-20         - conversion factor 220 CPM -> 1uSv/h (working voltage- 400V)
SI22G          - conversion factor 792 CPM -> 1uSv/h (working voltage- 400V)
SBT-9          - conversion factor 150 CPM -> 1uSv/h (working voltage- 400V)
SI-29BG        - conversion factor 122 or 112 CPM -> 1uSv/h (depending on batch) (400V)
SBT11          - conversion factor 250 or 318 CPM -> 1uSv/h (depending on batch) (390V)
SBT11A         - conversion factor 250 or 318 CPM -> 1uSv/h (depending on batch)(390V)
SBT10          - conversion factor 1250 CPM -> 1uSv/h (380V)
SBT10A         - conversion factor 1250 CPM -> 1uSv/h (380V)
SI8B           - conversion factor 1250 CPM -> 1uSv/h (380V) 

M4011 = 153.8? = 0.0065

J305b = 0.00812037037037

LND712 500v?

1 / 0.0057 = 175.4 CPM / uSv/h
1 / 175.4 = 0.0057 uSv/h / CPM