When the Saint Louis Zoo needed reliable level measurement of their animal water exhibit tanks, they turned to Flowline. The exhibits are largely open to the environment, subject to rain, snow and significant temperature swings. The primary level challenge is evaporative water loss, accelerated by heat in the summer, or condensing morning fog in the spring, winter or fall. Depending on their size and exposure, exhibits lose up to 500 gallons per day, which must be automatically detected and replenished. Zoo staff were dissatisfied with a different brand of ultrasonic level sensors, that became intermittent, when condensation formed on their transducers, and attenuated their acoustic signals. For this reason, Flowline suggested the use of our reflective ultrasonic sensors that are unaffected by condensation. The ultrasonic sensors provide continuous level data to the PLC, which monitors the exhibits and controls the fill valves. Flowline is reliable level measurement.