The ACI Transmitter Immersion Series features a two-wire, 4 to 20 mA loop powered output signal with optional three-wire voltage output signal available. All transmitters include Zero and Span adjustments for field calibration and are calibrated using NIST Certified Calibration equipment. We recommend the use of an 18 to 22 AWG shielded cable for all temperature transmitter installations to keep noise from being introduced onto the signal lines. The sensor assemblies are manufactured using Etched Teflon colored lead wires and ACI's proven double encapsulation process to eliminate the effects of moisture on the sensors as well as increased response times from our high quality, thermally conductive epoxy. The immersion sensors "-I" include a welded thermowell but can be ordered without the thermowell "-INW" version. The "-INW" includes a standard 1/2 Inch NPS process thread to be used with a machined thermowell or existing thermowell application. Optional NEMA/IP rated weather proof enclosures and NIST Calibration Certificates are available when ordering the A/TTM Series transmitters as referenced in the ordering grid on the back of the product data sheet. For best accuracy, ACI recommends the use of the A/TTM Series Matched transmitters which includes a 3 or 5 Point NIST Calibration Certificate, since they include a second calibration step in which the RTD and transmitter are calibrated together as a system.