The asphalt level tank gauge manufactured by Tonka Bay Instruments, Minnetonka, Minn., is designed to eliminate the operator’s having to climb onto a liquid asphalt tank while tank sticking. The unit, which consists of a tank gauge, middle, rear and front ports, clear and red sensing lines, horn, shut-off valve and conductor pipe, is powered on a 120 AC line. The conductor pipe can be retrofitted into horizontal or high vertical tanks in or out of service. For conductor pipe installation, the worker unscrews and removes the 3 inch (75 mm) pipe cap from the top of the tank. Away from the tank, he then torches a hole to pass a 2 inch (50 mm) diameter pipe through the pipe cap, and inserts the conductor pipe through the cap. The pipe is welded to the cap and inserted a distance just short of it meeting a coil obstruction or the tank floor. The pipe cap is replaced with the pipe suspended from it. The pipe can run about 1 foot (0.33 meter) above the pipe cap. The worker finishes the installation by attaching sensing lines to the system and the gauge is then ready for readings. A transmitter provides a signal to a small computer that scales the signal to readout digitally in tenths of inches (mm), gallons (liters), tons (metric tons), or the like. Equipped with high-level alarms, the unit can warn personnel of impending problems. The tank level gauge is designed to offer continuous monitoring of the tank level from inside and/or outside the control room.Tank outage charts and asphalt meters can be cross-checked for calibration accuracy, says the manufacturer. The sensing line is made of 0.25 inch (6.35 mm) diameter nylon tube The liquid asphalt level is sensed by back pressure from metered gases.