These graphs show the distribution of EMI measured 
voltages V1 and V2 required to obtain sensitivities of 
50 A/lm and 500 A/lm respectively.  PMs with SbCs dynodes 
are shown at left and PMs with BeCu dynodes at right.  
The centroids and sigmas are as follows:

PMT       V@50A/lm    V@500A/lm   

SbCs      1451(170)   1888(292)
BeCu      1754(97)    2310(171)