extraneous signals arising from any cause which might be confused with the required measurements, eg in electrical measurements or nuclear phenomena and of radioactivity, it would include counts emanating from amplifier noise, cosmic rays and insulator leakage
Good to know
DE: Nulleffekt [T45102]
FR: effet nul [T45102]
FI: tausta [T45102]
A larger number of counter tubes than will later be needed are each filled with 10 ml of 14C-free synthesis ethanol and 10 ml toluene scintillator. Each is measured for at least 4x100 minutes. Tubes whose backgrounds vary more than ±1% rel. from the mean are discarded. Only tubes new from the factory and from the same batch may be used.