The SI-7000 LTD is the ultimate solution for tank top level , temperature , and density profiling in the expanding LNG and LPG markets . Developed by cryogenic measurement experts at Scientific Instruments , this third-generation LTD prioritizes reliability and low operational expenses . Unlike competitors , it features discrete sensors for level , temperature , and density within a single probe , continuing the legacy of its predecessor , the Model 6290 . All components exposed to Zone 0 or Zone 1 environments are stainless steel , ensuring superior corrosion resistance . The drive mechanism utilizes a new robust ANSI-style stainless steel chain .