Instrumentation ○𓆪 ❪✺❫ Instrumentational Concepts ○ ❪𖣐₂❫ Instrumentation ○ ❪✺❫ Instrumentational Concepts ○ ❪✺₁❫ Instrumentational Classes ○ ❪✺_❫ Instrumentational Subs ○ Photon Counting ○ ❪✺₁❫ Instrumentational Classes ○ ❪𖣐₁;❫ Classes of Instrumentation ○ Gas Counter ○꠹ ❪✺_❫ Instrumentational Subs ○ Proportional Counter ○꠹