The UniProbe Flow-No-Flow Switches, Models UP01, and SP01 are sensitive to the heat dissipation of a fluid. The stainless steel probe houses temperature sensors and a heater element. This combination monitors changes in heat transfer to the fluid. The rate of heat transfer is proportional to the flow rate; therefore, a change from flow to no-flow is detected by the amplifier and causes a relay to switch. The relay contacts may be connected to operate a warning, shut down equipment, or control a process parameter. The UniProbe Flow-No-Flow Switch is user-selectable for liquid or gas operation and comes factory-adjusted