Method and apparatus for programming liquid scintillation spectrometers

Claim 1

In a scintillation spectrometer for automatically and sequentially handling and counting a multiplicty of radioactive samples, including A. a sample counting zone, B. means for counting said samples individually in said counting zone, including 1. means responsive to radioactivity decay events for producing electrical pulses having an amplitude related to the energy of corresponding decay events, 2. an amplification-discrimination channel receiving said electrical pulses, said channel having a. an electronic amplifier for amplifying pulses from said event responsive means, and b. upper and lower level discriminators for passing only a selected amplitude band of amplified pulses therethrough, and 3. means for counting discriminated amplified signals as a measure of the number of said decay events, C. a first analog parameter control for controlling at least one of (i) the gain of said electronic amplifier, (ii) said upper level discriminator and (iii) said lower level discriminator, and D. means for transferring said multiplicity of samples in a plurality of sets to said sample counting zone for individual counting of samples, the improvement whereby at least one of the pulse amplifying amplifier parameters is programmed to effect counting of samples within each set at at least one predetermined analog parameter different from parameters for other sets, which comprises: E. a replaceable analog parameter control having predetermined control settings and associated with an individual one of said plurality of sets, F. means for determining the particular one of said sets then having its samples transferred to said sample counting zone, and G. means responsive to said set determining means for disconnecting said first analog parameter control out of, and for connecting said replaceable analog parameter control into, said amplifier-discriminator channel.