| 摘要 |
It is proposed that scintillation counters are used to detect beta and gamma radiation, which are sub-divided, on the basis their maximum radiation energy into soft (B1,G1) and hard (B2,G2) groups. Radiation energy is measured and the results processed, separately, for each group. The ratio of the number of impulses detected for soft (iB1) and hard (iB2) beta radiation is used to correct the concentration of isotopes with hard gamma radiation (Kg2). With the aid of (Kg2) the value of short (Kr) and long (Kh) half-life of the gamma isotope concentration can be evaluated. The permitted concentrations (Sza,Szb,Szgr,Szh) are compared as types. The measured and calculated values (Ka,Kb,Kr,Kh) are found and the food being investigated is categorised as: consumable, not consumable and not consumable at present. The proposal also deals with the equipment being used: The proposed equipment is made up as follows: the output of a scintillation detector (1) is connected to the input of a peak rectifier (2), to the input of a signal width measuring unit (3), to the input of an amplitude-discriminator (4) and to one of the input connections of a signal width comparator (5). One of the input connections of the amplitude sample receiving station (6) is connected to the output of a peak rectifier (2). Its other input is connected to the output of an amplitude discriminator (4). Its third input is connected to one of the outputs of a micro-computer (10). One of the inputs of a signal-width-sampling store (7) is connected to the output of a signal-width-meter (3). Its 2nd input is connected to a signal width-comparator's (5) output. Its 3rd input is connected to another output of the micro-computer (10). The input of an amplitude analog-to-digital converter (8) is connected to an output of an amplitude-sample-store (6), which at the same time is connected to the other input of the signal width-comparator (5). The input of a signal width analogue-to-digital converter (9) is connected to the output of a signal bandwidth sample store (17). One of the inputs of a micro-computer (10) is connected to the output of an amplitude analogue-digital converter (8). Input of the micro-computer (10) is connected to the output of an amplitude analogue-digital converter (8). Its other input is connected to an output of a signal bandwidth analogue-digital converter (9). The third output of the micro-computer (10) is connected to the inlet of a signal display unit (11). |
