customer has a gas station with wiring for probes/sensors ran with belden cable 88760 directly buried in ground no conduit. The cable may or may not be rated for direct burial but I was wondering if the installation in it self is code compliant. The issue customer is having is that when cars drive over area it sets off the alarms for probes and sensors and they want us to replace wiring with new direct burial cable my question is do I need to install wiring inside conduit all the way to probes? I believe I need a seal off at entry in to store and the intriniscally safe wiring can be wired under normal wiring methods but I feel I am missing something when I deal with C1D1 areas. The store is exisitng and at least 20yrs old. The probes dont lead into STP tank sumps but are part of the intrinsically safe circuits that sit outside tank sumps. I am hoping to get some advise from people who have dealt with gas station construction. I searched Article 504 but cant find anything that sticks out.