The ACI Thermistor Duct without Box Series features a stainless steel probe with two 22 AWG Etched Teflon colored lead wires to dierentiate the different sensor types. The sensors in this series are manufactured using ACI’s proven double encapsulation process to eliminate the effects of moisture upon the sensors and increased response times using our high quality, thermally conductive epoxy. The duct style sensor is designed to be used in smaller duct applications and includes an insulation pad for sealing your duct as well as to dampen vibration. For best results, the sensor length should be determined by the actual width or diameter of your duct such that the tip of the probe is in the approximate center of the duct. On larger ducts, you may want to refer to our Rigid or Bendable Copper Averaging sensor for increased sensing points and better temperature control. The Duct without Box Series can be ordered with optional plenum rated cables and NIST Certificates.