when a wastewater treatment facility has a highly corrosive environment, it is fiscally appealing to forego the eventual refrigerator repair costs and just use a disposable refrigerator. This is why the tc-4 models replace the marvel™ stainless steel refrigerator from the tc-3 with a stainless steel stand and disposable refrigerator. The tc-4 dual is a composite sampler designed to sample two lines of waste or process water. The tc-4 dual uses two pneumatic arm assemblies to sample the water as it flows through the reservoirs. One of the key features of the sampler is the unique design of the flow-through reservoir. By design, the reservoir creates turbulence in the area that is sampled. This turbulence ensures that suspended solids of all sizes typically found in wastewater flows are available for sample. As a result, the sample obtained is a true representation of the actual flow. Once the sample has been collected, it is gravity fed to a 2. 5 gallon jug stored in the disposable refrigerator. A bottle full alarm can be used to stop the sampling and allow a new jug to be placed in the refrigerator.