Measurement apparatus employing long-line call-up system

Claim 1

APPARATUS FOR MAKING MEASUREMENTS AT A PLURALITY OF SUCCESSIVELY DISPLACED REGIONS HAVING, IN COMBINATION, A TWO-CONDUCTOR LINE; A PLURALITY OF SENSING MEANS DISPOSED AT SUCCESSIVE DISPLACED REGIONS ALONG THE LINE AND PERMANENTLY CONNECTED WITH AT LEAST ONE CONDUCTOR OF THE LINE; A CORRESPONDING PLURALITY OF SIMILAR ADVANCE CIRCUITS EACH PROVIDED WITH ENERGY STORAGE MEANS AND NORMALLY INEFFECTIVE RELAY MEANS; A SOURCE OF SUCCESSIVE ELECTRICAL IMPULSES; A CORRESPONDING PLURALITY OF SWITCHING MEANS FOR CONNECTING THE OTHER CONDUCTOR OF THE LINE TO A FIRST OF THE PLURALITY OF SENSING MEANS TO ENABLE A MEASUREMENT THEREOF THROUGH THE LINE AND FOR CONNECTING THE SOURCE TO A FIRST OF THE ADVANCE CIRCUITS IN ORDER TO ENABLE A FIRST IMPULSE FROM THE SAID SOURCE TO ENERGIZE THE ENERGY STORAGE MEANS THEREOF AND, UPON TERMINATION OF THE IMPULSE, TO RENDER THE CORRESPONDING RELAY MEANS THEREOF EFFECTIVE; MEANS RESPONSIVE TO THE EFFECTIVE RELAY MEANS OF THE SAID FIRST ADVANCE CIRCUIT FOR CONTROLLING THE CORRESPONDING FIRST SWITCHING MEANS TO DISCONNECT THE SAID FIRST SENSING MEANS FOR THE SAID OTHER CONDUCTOR AND TO CONNECT A SECOND OF THE PLURALITY OF SENSING MEANS AT A DISPLACED REGION ALONG THE LINE TO THE SAID OTHER CONDUCTOR TO ENABLE A MEASUREMENT THEREOF THROUGH THE LINE WHILE CONNECTING THE CORRESPONDING SECOND ADVANCE CIRCUIT TO THE SAID SOURCE.