GB1371761A - Checking of meters - Google Patents

Abstract

1371761 Reading and checking meters for registering road charges NATIONAL RESEARCH DEVELOPMENT CORP 14 Jan 1972 [29 Jan 1971] 3491/71 Headings G4D D6Y D1D11 and D4A2 Apparatus for checking and reading a road usage meter on a vehicle comprises means for reading the meter and meter identification, means for applying an input which will advance the meter, if faultless, by a known amount and means for rereading the meter and comparing the difference between the two readings with the applied input. The "known amount" may be varied and the apparatus may show an error in meter reading immediately or, all the information may be stored on tape and sent to a central processor for calculation of amount owed. As described, the meter is operated by inductive loops buried in the road. The meter is a four decade counter with position encoding. The apparatus is connected to the meter by a plug which has 24 connections; four from lead 5 which connect, one to each decade; ten from lead 3 which connect to each position on each decade, like numbers on each decade being connected and ten from lead 6 which are fixed connections on the decade output positions so that they represent a number characteristic of the meter. A potential from terminal 31 is supplied in succession by contact 30 of switch S1 to each of the identification leads (lead 4) and to each of the decades (lead 5) and the resulting output is either displayed on fourteen display devices, each of which can display any digit from 0-9 or is converted to binary and recorded on tape. In operation, the meter identification and initial reading are read as described above. The number by which the counter is to be advanced is set in store 36 and oscillator 16 is set in operation, supplying pulses through transmitter loop 10 to the meter. These pulses pass to the tape and also to counter 34 from which they are fed to coincidence detector 35 which stops the pulses on coincidence between the count and the number in store 36. The new meter reading is taken; S1 scanning only the ends of lead 5 and this reading is again recorded on tape. A fault detector 39 may be used to signal incorrect operation of the meter.