The ACI Platinum Duct Series features a stainless steel probe with Etched Teflon colored lead wires to differentiate the different sensor types. The three-wire “-3W” option should be ordered when using with a 3-Wire temperature transmitter or sensor configuration on your building management system or PLC (Programmable Logic Controller). The purpose of the 3rd wire is to compensate for external lead wire resistance that will affect the accuracy of your sensor output. ACI recommends the use of an 18 AWG lead wires to reduce the external lead wire resistance when using a Platinum RTD. The sensors are manufactured using ACI’s proven double encapsulation process to eliminate the effects of moisture on the sensors and to increase response times using our high quality, thermally conductive epoxy. The duct style sensor is a single point sensor designed to be used in smaller duct applications and includes an insulation pad for sealing the duct and dampening vibration. The sensor length should be determined by the width or diameter of your duct, such that the tip of the probe is in the approximate center of the duct. Standard enclosure options include the “-GD” Galvanized or “-PB” plastic enclosure with hinged cover. On larger ducts, our Rigid or Bendable Copper Averaging sensor may offer better coverage based upon the size of your duct system and sensor location. Optional NEMA/IP rated weather proof enclosures and NIST Certificates are available as referenced in the ordering grid. Applications: Roof Top Units, Air Handlers, Monitoring Supply/Discharge/Return/Mixed Air Temperatures