GB900850A - Improvements in electronic counting arrangements - Google Patents

Abstract

900,850. Registering output of machines. LABGEAR Ltd. Feb. 27, 1959 [Nov. 29, 1957 (2)], Nos. 37277/57 and 37279/57. Class 106 (4). [Also in Groups XL (a) and XL (b)] In a system for comparing a quantity with a reference quantity, the quantity to be measured is represented by a series of pulses which are registered on a counter giving a visual indication of the count. Means are provided for producing the reference quantity, and on attaining this quantity the counter is stopped and the reference quantity and the count compared. The counter operates indicating devices if the count is outside limits set in relation to the reference quantity. In one embodiment the output of a detector 3, Fig. 1, which receives radiation from radioactive samples 1 passes to a counter 4 which is set in operation by unit 5 for a period corresponding to the time in which a standard sample is known to give a certain count, this count being a reference count. The count is indicated on counter 4 and if it differs from the reference count by more than a certain limit the indicator 7 or 8 is operated. The indicators may be visual or aural. In a second embodiment a standard sample actuates a second counter, Fig. 2 (not shown), while the first counter monitors the sub-standard sample. The second counter, after attaining a certain count, closes a gate between the detector and the first counter. For monitoring radio-activity at several points, the system of Fig. 3 is used. The time during which each channel is monitored is selected by a selector 32, and counters 20, 21 register the count detected by unit 27 in the appropriate location, the channel being chosen by unit 35. The reference counter 34 operates gate circuits 26 in the manner described for the second embodiment above. Should the count recorded in a channel be outside set limits a warning indicator 24 is operated and a printer 22 prints information relevant to that channel. Indicators 23 or 25 operate if the difference between the channel and the reference counts becomes excessive. A further counter may be used to monitor the channel continuously if any of the indicators 23, 24, 25 is operated. The system of Fig. 3 may be used for sampling gas drawn from the neighbourhood of fuel elements in a nuclear reactor and may initiate automatic shut-down in the event of fault.