Question: This question applies to level gauges for portable tanks. “What are the possible alternatives of level gauges we could install on our T11 24000 liter tanks. Would a Scully system work for this?”
Tank Guru: Scully systems are mainly intended just as overfill protection (high-level alarm) and do not provide a continuous indication of the product level. When considering level gauges, the options are somewhat limited on portable tanks because of the lack of electrical power, and the need to have something that will hold up to the rigors of transportation service (shock, vibration, etc.). Not to mention that in a stainless steel chemical tank, most customers are going to want a gauge with all SS wetted parts.
So there are basically 2 practical options: float gauges, and ultrasonic or radar technology. There are a handful of float gauges available for transport tanks that vary from basic mechanical devices which have a long arm inside the tank with a stainless steel float that magnetically operates a simple dial (indicates percentage of tank volume); to a precision gauge where the float travels up and down a sender bar which is calibrated to display the actual volume of liquid inside the tank (either liters or U.S. gallons).
Another option is the radar gauge, and as with the float gauge there are a couple of different ways you can go – either guided wave radar or microwave loop (non-contact). There are pros and cons of one technology versus the other, and a lot of it depends on what will be transported in the tank and whether you have the ability to anchor the probe used in a guided wave system to the bottom of the tank; but in general one big advantage of radar systems over the float gauges is that there are no moving parts. The disadvantage is that these systems typically cost more than a float gauge.