R TraceTek Leak Detection Product Selection Guide for Water

R TraceTek ®Operating Principles for LeakDetection and Locating SystemsTraceTek Sensing CircuitLeak DetectionThe sensing cable has two insulatedwires and two conductive polymer coatedelectrodes.A small DC voltage (5-9 volts) is appliedto the sensing cable, and internalresistors limit the current flow through thesensor cable loops to approximately 75microamps. The actual amount of currentflowing is monitored by measuring thevoltage drop (V 1 ) across an internalreference resistor.If a spill occurs, additional current willseek the path of least resistance and flowacross the leak. This results in increasedcurrent flow through the referenceresistor. The resultant increased voltagedrop across the reference resistor signalsthe module to turn on the alarm.Continuity MonitoringIf the cable is broken, no current will flowin the loop. The voltage across thereference resistor decreases to zero andthe internal circuitry recognizes this as acontinuity fault.+V 10.2ContinuityNormal0.8Leak detection is accomplished by monitoring thevoltage across an internal reference resistor.LeakLeakLeakV 1 meter readingLeak Location+After a leak has been detected, thecircuitry in the module is automaticallyreconfigured into the locating mode.The digital readout of the location isgenerated by measuring the voltage dropalong the sensing cable between the leakand the module. The voltage drop islinear and proportional to the leaklocation. A different scaling factor isapplied for feet, meters, or zones.Raychem CorporationCommercial & Industrial Infrastructure Division300 Constitution DriveMenlo Park, CA 94025-1164Tel (800) 545-6258Fax (800) 611-2323www.raychem.comV2Leak location is determined by measuring voltagedrop along the cable from the module to the leak.Distance read-out isproportional to V2© Raychem Corporation Printed in USA 8/93 H54534